Starter

Well having assured myself now that there was no basic fault with the car's electrical supply and restored function to most of the ancillaries, I had no more excuses, its time to venture under the bonnet to look at the starter problem!

The starter had been dead since I got the car: The scenario- turn on the key- all ign waning lights come on... click over to starter position and all dash lights dim but no sound and no movement from the motor! Obviously the battery had been my first suspect but this was now new (Exide high capacity) and fully charged. A poor earth was another and quite likely possibility so I ran a jumper lead from the starter body directly to the chassis- no difference. As I was sure battery positive supply was good (nice bright headlamps/lights) and the ign switch was obviously connecting something (power appeared at red/white lead on solenoid when switch activated) it was time to remove the starter.

...and here Dear Reader, begins to unfold a catalogue of woe. Prepare yourself for an account of superhuman strivings coupled with ultimate failure! An allegory perhaps for the human condition and the lot of all mankind!!

OK well maybe not that bad- first remove the starter- In most cases this process will start with removal of the airbox but as mine was conveniently already in the boot this was a help!

I disconnected the red/white lead at the spade connector on the solenoid and then removed the High current leads from the solenoid pole- one from the battery supply and one to alternator. These leads are connected via threaded copper studs but the nuts appear to be harder than the copper. The stud threads distort as the nuts are tightened and so undoing the nuts tends to strip the threads from the stud- This has happened routinely to me anyway and I can't find a way of preventing it. If anyone knows please let me know too! As it is I made a mental note to re-thread the studs at a later date. The motor is held on by just two bolts and a 17mm socket on a U/J plus a long extension got to them. Unfortunately these are bolts with non-captive heads, and you will need a stubby spanner to reach over the bell-housing and hold the heads from behind whilst you unscrew the nuts with the socket. Don't forget to support the motor with your third arm as it comes free!

The motor came off relatively easily, so over to the bench for a closer look.

Rear of starter motor- sideways though- oil filter towards top

Heated Rear Screen

Heated rear Screen

The last of the interior electrics that needed attention was the heated rear screen- the switch had remained resolutely dead which could either be the bulb or the relay. I checked the relay first as its easier to get at, and straight away suspected a problem. It just wouldn't pull out of the bank. Much persuasion later it eventually came free revealing horrid rusty terminals. I checked the relay as before and found no activity at all! There was power to the base so I cleaned that up as best I could, working the relay spades around in the slots an then spraying contact cleaner to clear any dislodged muck. Finally I inserted a new relay (Chinese, cheap and functional) and at once the HRS light came on and winter de-icing function restored!

Wiper Parking

Those of you glued to this blog will recall that I had managed to get the wipers working on both speeds and flash wipe, but that the parking mechanism didn't work.
Seems that these Lucas wipers have a detachable parking switch that is the devil to get to.... on most Excels. Luckily on this early model the wiper motor is simply accessible from the passengers footwell once the under dash cover is removed.- since my cover was always hanging off this was no significant problem!

Wiper motor seen from passenger's footwell. Park switch is white plastic assembly on left, served by 3 wires and a multiplug

Detach switch, note bar across motor body slot that is gripped by the clip on the switch body

Plunger switch on underside of switch body

Rear of switch showing mounting clip and small square "cleaning" hole below and to the right of the clip

The park switch is the small white plastic unit fixed to the motor and connected to 3 wires (spades) and a multiplug. Most articles will tell you to "pull this off" or "unclip" it. In fact its held very simply with a clip on the rear but this is a sliding fit There is a bar across the motor opening that a clip on the back of the park switch fits over. so you have to pull it gently downwards (ie away from the motor body) and then slide it sideways in the direction of the multiplug end.  Its one of those fittings that's obvious once you've taken it off (if you haven't broken the clip in the process).

The switch has no serviceable parts and doesn't come apart, but given the success of simply cleaning I opted to try that first.  I could direct a jet of contact cleaning fluid into the switch through a small squarish gap in the underside I shook the switch vigorously and operated the plastic plunger repeatedly before shaking the cleaning fluid out- it was a very satisfactory grey colour (motor brush dust?). Anyway I repeated this three times before shaking the last lot out and letting the switch dry thoroughly- I've no idea if this fluid is flammable and no wish to find out! I then refitted the switch, attach wires first then push it in and slide along to let the clip grip. A simple (surprisingly so) job and hey presto parking function returned!

If you have to replace these switches its worth shopping around, they are pretty common and mini replacements will fit - Lucas number 520160A for two speed wiper systems. 

Horn compressor overhaul/repair (Hella)

The horn on my car (like so much else) was non-operative when I got it. I had fiddled briefly with the wiring but although I got a burble, any sound was short lived and it soon became silent again. I quickly worked out that I had 2 faults:

Firstly the relay operation was erratic.!when it works there is an audible click when the horn switch is operated. In my car this relay is located on the right hand side in the driver's footwell. Changing the relay sometimes helped but even a known good one didnt always restore function. I could detect power at the relay power "in" pin but can't check supply to the switching circuits as I have an insufficient number of hands to probe the relay socket whilst also operating the horn button.

Secondly: Applying power to the relay power-out socket failed to rouse the horn- not a peep from the compressor so this has obviously failed too!

I couldn't find much on servicing a horn compressor- maybe they are usually replaced as they are cheap enough and readily available- however I thought I'd have a go and so stripped the horn out of the right-hand pod. The horn blower is mounted at the back right of the pod cavity bolted onto the plywood bulkhead. The rear bolt is inaccessible but for once this doesn't matter as its only a slip-over mounting. Loosen the front bolt and lift off the compressor. It has two wires on the base. purple/white (power feed from relay to pump positive) and black (earth) from pump neg terminal. The purple/white was continuous back to the relay terminal and the earth was good. Nonetheless, applying  12V across the pump fresh from the battery still failed to get it moving, so clearly a pump fault. Simple jams can apparently often be fixed by adding WD40 in the air spigot- but my pump had plenty of oil and I suspect that route had been tried many times before! I think its time to delve deeper...

I started by unscrewing the 3 self tapping screws at the top. 

Top of compressor- oil hole and air outlet spigot

These secure the cover over the impeller which spins in an oil filled well. Sliding vanes in the impeller maintain contact with the sides an eccentric well, scooping up air and expelling it to the small cavity under the outlet spigot.

Impeller cavity- note vanes in rotor, oil sponge and spacer in side cavity

I found no gasket here but I think there should be something given all this oil- again maybe someone has been here before me? In my pump the impeller rotor and motor shaft wouldn't turn at all so obviously a fault. The rotor is stiff but will pull off the shaft. Its keyed to the shaft with a small ball bearing that fits in a drilled out hollow- so catch this when it falls out and keep it safe.
Turn the motor over and loosen the two slot-head screws beneath.

 The top cap with rotor cavity will now come off but it might need a tap first. As the cap comes off the motor armature is revealed, and in my case was in a shocking state, jammed with rust and muck. The armature simply pulls out although you have to pull against the magnets and any jamming muck so it can be very stiff.

Pump body with armature removed, brushes just visible in base, sides covered in rusty magnetic debris!

Armature removed and cleaned, polished commutator with emery and cleaned  bearing surfaces

Clean the case thoroughly... this very difficult to do as its lined with 2 powerful magnets and the rust is magnetic too! I found it useful to scrape the sides with a screwdriver and then use a magnetic pickup tool to remove the rusty debris. I got it cleaned up as much as I could- much better anyway- and then I smeared corrosion block grease on the inside but not on the magnets.

The motor brushes are awkwardly located at the bottom of the case and hide the lower armature shaft bearing. My brushes were in good order so I carefully pushed them back in their cases and cleaned the bearing. Last job clean up armature and the brush commutator region.

Reassembly is tricky because of the brushes. I made a forked spring from a cable-tie.

Tool made as described. May need to trim the branches to get a good fit

Make a 2 cm loop and cut this to make a "Y" shape. then fold the tail of the Y across itself and clamp the fold in a vice to fix it. This puts a 90 deg bend near the Y and forms a handle that can extend up the side of the case between the magnets. Insert the springy Y between the brushes pushing them back clear of the lower shaft bearing hole.

Tool in use, note how brushes are pushed back into their housings, - these need to go back a little more to clear the bearing entry.

Carefully insert the armature (great care as the magnets try to grab it) until the lower end slips past the nylon Y and into the bearing. You can then pull the cable tie up the side as you slip the armature fully back down. Make sure you have removed all the cable tie (its a bit brittle) and that the armature can turn freely. This is a bit fiddly so I would test it before screwing up the case. I just placed a finger lightly on the end of the armature spindle and briefly applied 12V to the motor terminals to make sure it spins. When the armature is fully down its shoulders will be below the top of the magnets but I found this didn't really happen until I fitted the top and tapped it down. Something clicked and in it went- no idea what it was! Check rotation again and then refit the impeller. I found that if you hold the pump body horizontal with the ball bearing hollow in the shaft uppermost, the ball bearing will stay in place while you slide the impeller over it (lining up the bearing and its slot first). The blades are bound to fall out at this stage so refit them making sure that they are the right way round to scrape the walls closely as they rotate (anticlockwise in this case). The direction is obvious since they have to scoop air towards the outlet point. They are bevelled on one side to improve their fit with the wall- again its obvious. Add some oil, reinstall the oil sponge and its spacer and finally refit the cap with the 3 self tapping screws. I found this final step trapped the impeller and stopped it turning so I suspect there should be a gasket here.

I refitted the pump and connected it up to the air-hose and horns. Although the relay still doesn't work (job for next week) I applied 12V to the relay's outlet contact and was gratified by the ensuing horn blast  which brought  my neighbours running from their back gardens to investigate!
OK so its a cheap component but I reckon it should now last for another few  years!

Headlamps- part 2

I should say something more about pod removal.
Its pretty well straight forward but a better way to remove the connecting rod is to do so at the bottom. This joint is referred to as a "ball joint" but on these early cars its not actually a ball joint  at all- In fact this is a screw on yoke-eyebolt which pivots on a shaft from the motor actuating arm. Best procedure is to reach into the pod and unscrew the retaining nut and washer before pulling the eye bolt off the motor shaft. This allows the pod to be moved easily and indeed removed when the mounting bolts are taken out. What's even better is that this doesn't affect the adjustment at all when its refitted! To refit I found it easiest to attach the actuating rod back onto the motor lever and then wind the motors up or down by hand until the pod and bonnet bobbins coincided- it was then easy to screw the bolts through.

Adjustment yoke bolt on motor actuating rod. Best to make sure this is clean and greased and so turns easily to make adjustment easier.

Also I found that the nut on top of one of the connecting rods had stripped so I will retap this and fit a new nut, but if you can avoid it, don't remove this nut as refitting is a bit fiddly owing to the spring tension..

Headlamps Part 2

Having removed the pods the motors will easily follow, they are held onto the mounting bracket by 3 small bolts (10mm) and washers. Support the motor as you remove the bolts, its surprisingly heavy. I don't pretend to have understood the action of the headlight pods which owes much to the dark arts. Lotus need several pages of wiring diagrams to explain and I will not reproduce those here but try to read this text in conjunction with these pages and maybe it will help. Here is my best analysis.

Wiring diagram pod motors- G- green, N brown, U-blue, B -black

Firstly the power feed to the motors is not affected by the the column switch - it doesn't even pass through the lighting switch. However when the pods are not moving this motor feed is interrupted by the relays (one for each headlamp). The lighting switch actually controls the switching current to the relays which in turn connect or interrupt the power feed to the motors. However its not a case of "on" or "off" because power is also always applied to the switching circuit, but this  circuit is in its turn interrupted by the two micro-switches in the motors themselves (one for "pods up" and one for "pods down"). This means that when the pods are still in either up or down position, the switching current to the relays is broken by the micro-switches, relays remain open, interrupting power feed to the motors.   In this open state the relays actually earth the motors to prevent or control any possible movements when not required. The final complication is that despite the terms "up" and "down" for the micro-switches in the motor, the motor actually turns in the same direction all the time. It simply rotates between two fixed positions which are set by the micro-switches which interrupt the relay switching circuit when the motors reach the next set position. - So far so  clear? Well maybe not, and I still can't get my head around the flash circuit and how the lights are actually turned on but its a useful approximation.

If we think about one pod motor only, then there are 5 wires that go into it, 3 are routed through a multi-connector and  2 join via individual connectors. In my wiring diagram the left and right headlight motors are shown with different colours, but in the actual car both sides were wired the same and both used the scheme shown for the right headlight motor so I will use these colours in this description. The two individual wires take power from the lighting switch to the two micro-switches in the motors.  One of these wires (Brown/green) is live when the column switch is "off", and the other (blue green) is powered when the  column switch is "on".  Although there are two micro-switches, they are actually joined together by a copper strip that functions a little like a see-saw.

Cover removed from motor to show microswitch and individual wire feeds that supply contacts at each end of the copper strip. White nylon plugs are invisible beneath the copper strip.

 The two feed wires above supply contacts at each end and when the see-saw touches down at that end then power flows up the seat of the see-saw  and out through the pivot point where a green wire is attached. This wire is the centre wire in the three plug multi-connector and takes the power into the relay circuit. No matter which direction the pods are travelling their motor relays are always fed via this green wire, what changes is the end of the seesaw from which the green wire is receiving its power. In our example when the pods are down then the seesaw is tilted towards the "up" microswitch closing contacts at that end and breaking contact at the other. Operating the column switch then connects power to the blue/green wire connected to the ""up" microswitch. Since this switch is closed power can then flow up the seesaw and out via the green wire to the motor relays  (one after the other). This causes them to close and so connect the power (via the black/green wire in the multiconnector). Power flows through the motors causing them to turn and then out to earth via the remaining wire in the 3-prong plug, the black earth wire.
The motors then begin to cycle, and as they turn, gearing within them raises or lowers two plastic plugs which push on the arms of the see saw. As the pods rise the plug on the side of the "up" switch starts to rise whilst that on the opposite side starts to retract. Just as the pods reach fully "up" the plastic plug has risen sufficiently to push up that side of the see-saw and  break contact at the "up" micro-switch. This interrupts power supply to the relays which therefore spring open again cutting power to the motors and thus stopping them with the pods in the "up" position and headlamps on. In fact when these relays open they actually earth the motors so that movement is stopped immediately.
Just as contact at the up micro-switch  has been broken by the rising of that plug, the retraction of the plug at the opposite end has allowed the see-saw to sink, closing the contacts at the "down" end. Whilst the column switch remains in the "on" position there is no power feed through this contact, but this changes when the lights are switched off. This action then sends power  to the "down" microswitch which can then  run up the see-saw and out via green wire to close the relays and start the motors turning again. This action will then lower the pods whilst the geared movement in the motor raises the plastic plug on the "down" side of the see-saw until this breaks contact between the see-saw and the "down" switch, restoring contact at the "up" switch. Once more when contact at the "down" switch is interrupted, the relay current collapses and power to the pod motors is cut, stopping the pods in their newly lowered position. I think the switch must be arranged such that both switches are actually connected during pod transit (either up or down) because this is a requirement for the flash circuit (see below). Also if it were not so then turning the switch off during pod up movement would cause the pod to freeze in a partially open position

This then is my understanding and lead me to the following test procedure. My Sealey PP1 probe has now been delivered... and its fantastic- just right for this protocol and given the potential for the legion of electrical faults possible in any Lotus, I would suggest that this or something similar is essential kit for any Lotus owner!- No I'm not on any profit sharing scheme!

1. Check relays. Test or replace all relays with known good ones. If you can't do that try changing them over- if only one pod is affected does the fault switch sides if you switch relays? Trace the wiring though to identify the relays- mine were arranged in a different order from that shown in the manual.

Relay pin designation

Testing is relatively simple. Place the relay  upside down and orientate it with the single edge-on contact (30) towards you at the front. Connect a conductivity meter between this contact and the centre contact (87a) it should read connection. Test between the front and the rear contact (87) in this centre row- there should be no connection. Apply 12v between the side contacts (85 and 86), the polarity doesn't really matter. Listen for an audible "click" and check that contact has now been made between front (30) and rear (87),  and broken between front (30) and centre (87a). If all checks out the relay is good, but even so make sure the pins are clean and rust free and do your best to clean the relay mounting block slots too-if anyone knows a good way to do this, I'd appreciate the heads-up!
2. Check motor. Disconnect  all the wires from the motor, apply 12v between the black/green (+ve) and the black earth (-ve) wires at the three pin connector going into the motor (take care not to short the supply wires). The motor should turn continuously, if not then the fault lies in the motor itself.
3. Check microswitches. Reconnect the three wire multiplug, look at the motor and see if the arm is in the raised or lowered position and thus in which direction the next movement should be. If its not  close to either of these positions turn it using the hand knob until it is. Apply 12V (+ve) to one of the single wires entering the motor (ie if arm is "up" apply feed to the "down" microswitch and vice versa). The motor should then turn until the microswitch breaks contact, e.g in this example the arm should move down and stop.   Then apply power to the other wire and check that the motor cycles back to its original position.  If movement is not achieved in the expected alternating pattern suspect the microswitch.

Flash relay

I cant fully get my head around this, but the flash relay is always connected somewhere. When the column flash switch is in its down position the flash relay  is in its open (unpowered) position and connects power to the "down" micro-switch circuit ensuring pods are lowered. When the column flash switch is operated it applies 12v across the flash relay to earth, causing the contacts to close. When these contacts close they disconnect the down circuit and connect the power to the Blue/green up micro-switch circuit raising the headlamps using the same current path as above. When the flash switch is released the flash relay springs back to energise the "pods down" circuit and the pods will lower.

The micro-switch presumably contains some cunning timing gears to ensure that both up and down contacts are actually in connection whilst the pods are being raised. This means that the "down" circuit always has access to the down micro-switch during "up" movement since if it did not, releasing the flash switch whilst pods were only partially raised (and thus energising the down circuit) would result in their freezing in this position. In other words (and here's where the see-saw analogy breaks down) the see-saw must be flat for most of the time that the pods are actually in motion.

Well that's my understanding anyway- I'm sure someone will point out my errors but at least it led me to a sensible testing procedure and located the fault.
In my case applying power to the motor showed that both could turn perfectly well. Applying power through the micro-switches showed that although the right motor responded to both, the left didn't respond to the "up" signal. I suspected a dirty micro-switch contact but cleaning gave no improvement. It was eventually tracked down to the nylon pegs that raise or lower the see-saw contact strip. One of these seems to have got some dirt on it meaning that it was too high and even when fully retracted, it did not allow the micro-switch to make contact! I cleaned the head of the nylon rod and all was well.**

I have since found that this rocker is the weakest point invthe system and most faults are due to dirt ir damage to the copper strip. Many can be repaired simply by cleaning or rebending the strip. However it is hard to bend the strip down whilst its in position and to get around this you can release it by carefully drilling iut the central rivet. Its easy to shape and clean it once its off and it can be refitted using a 6 ba screw and nut thriugh the rivet hole. Have the nut facing upwards where there is plenty if if room but you may need to reduce the moulded plastic boss on the underside to allow the screw head to sit high enough that it doesnt obstruct the rotation of the triggering system underneath.

I re fitted the pods and tested again- I had to lower one pod by hand so perhaps there is some sort of starting coordination position (?) but after that initial hiccough the pods and headlights are operating fine. Strangely I seem to have lost  horn function but I will try to track that down later. One last thing is that I noticed that on turning on the lights the pods seem to lower a little before they start to rise and I'm not sure why this should be- for the time being I will assume that this is normal behaviour!!!

Note added later...
Having checked the various forums on line I think the conclusion is that this lower-to-rise behaviour is common, although I still suspect there is an adjustment somewhere that could eliminate it. I also found this excellent account of how to service the motors on lotusexcel.net. Its written by member "fueltheburn" so I'm not claiming any copyright or originality- just passing on some excellent advice that I appreciated at the time.

Headlamps part 1

Headlights 
 After some fiddling with the switch I had managed to get the right hand headlight to rise and illuminate, but there was no progress with the left. Both headlamps can be raised manually using the knob on the bottom of the motor- take out the plug grommets under the wheel arch and insert your hands into this dark cavernous and (in my case) inhabited space. The knobs were faulty but I could raise the light manually  with only a little pain in my fingers. Once up, the light would power down when the ignition is turned on. However its time to investigate so headlamps off! There is little detail on how to do this (too simple I suspect) but since I worry about putting too much force in the wrong place- yes I've been there, this is how I did it:

Raise the headlight and detach the black plastic bezel- two press fit studs one each side easily levered out.

standard trim plastic stud rivets just pull out using finger pressure.

The headlamp is then "unclipped" although its wasn't immediately clear whether this meant at the rim of the light where the adjuster screws are or at the pod.- Its actually at the pod, amazingly the headlight just pushes into 3 pop-fit fasteners and can be carefully levered out- seems a fragile and delicate arrangement which suspect will fail if you have to take the lights off very often!

Adjuster screws are simply a push-fit into a nylon bush in the pod rim

Headlight removed and disconnected from loom, motor connector rod inside.

TThe pod is held on by two bolts at the back and moved by means of a cross shaft connected to the motor by a sprung rod. This incorporates an adjuster to set the "down" position. Someone had obviously been here before as the bolts holding the pod were only hand tight and there was a scattering of more debris in the pod- remember I had already removed some pliers and a spanner (as well as a mouse nest)- I now found a pen, spare bolt and several  Mars bar wrappers! Lucky this car doesn't move as this lot would have rattled around something terrible!

Next step according to my instructions was to "ease off the connecting rod". This is the sort of guidance I hate because it means everything to someone who has done this already and nothing to anyone who hasn't! Ease it off where? If you want to remove the pod surely you have to disconnect the rod- that's a sort of terminal easing off I guess? 

Cross-rod and adjusting rod with retaining nut on top. Base of rod screws into  threaded ball joint on the motor arm, note pod-retaining nuts only loosely fitted from LBPO previous repair attempt- does not bode well.

Anyway the retaining nut on the top of the rod was accessible although rusted solid. Undoing that screwed the whole rod out of the adjuster ball joint at its base so out it popped and the pod 

Pod cavity-- after emptying!

was easily removed. This revealed the motor at last... and also a badly decayed plywood bulkhead at the side. I am aware that these are often rotten, and mine sadly is no exception- I assume the other side will be the same so these will need to be changed. I guess someone thought that it was a good idea to put wooden panels into a GRP body rather than more GRP but time has not really supported that decision. If they were intended as a weak crumple point then they have clearly become self-crumpling over the years. I would have thought that in this day and age there must be a more suitable synthetic cellular sheeting that would be better- but I guess I will simply replace the plywood for more plywood (eventually).

The motor is another fitting with far too many wires- can it really need all these connections? Sadly there is no explanation of operating principle in the manual and the wiring diagrams are incomprehensible (to me anyway). Strangely the wire colours I found connected to this LH motor are actually those shown for the RH motor but the connections are presumably the same.  I tried to apply power to the motor directly but nothing I did induced any movement at all. A search of the web failed to turn up any procedure for testing the thing so I assumed that this will probably need to be replaced. Plenty of evidence that the LBPO had experienced problems as well- so I will probably need a new motor here.

So as before, I put everything back together. Very tricky to line up the rod and the ball joint adjuster while the rod is still connected to the cross shaft so I removed the rusted top nut, screwed the adjusting rod into the ball joint and then replaced the pod by fitting the rod to the cross member before finally inserting the bolts. I had to crank the motor a little with the hand control to raise the arm so that it could connect to the rod whilst my hand was still inside.

Reassembly went easily and with trepidation I tried the switch- Hey presto Both lamps rose at once!!!

Joy short lived- although both rose, the left hand now did not go down!

Suggestive winks from my project car- LH light pod will not retract.

I then started to crank it down by hand only to have the motor take over and respond to the suggested movement and power the pod down- more pain to fingers! This has to mean that the motor can work in both directions although it has trouble starting to move. Perhaps something is stuck or jammed internally? I have also found that on occassion I can get it to lower by disconnecting and reconnecting the battery? Strange behaviour indeed. I will also try cleaning the relay contacts. I have seen these motors stripped down so perhaps this is worth trying too? I'm fishing for any ideas that might be floating around out there off  Blogger-bank? 

I'm not sure where to go with this- have I fitted the light back with the motor in the wrong position? - ie motor now thinks its down when pod is up or vice versa? Since I can't understand the workings of this system I will have to do some more research- so once again I will return to this on a later day.

Incidentally whilst under the car I also noticed that the steering rack gaiters are split so I suspect it will need a new rack as well! The list keeps growing as I find new problems faster than I am fixing them! Hopefully this is just because I'm at such an early stage.

Luckily I am thinking of this as a long term project!

Well its been a few days- combination of bad weather  and kids half term (naturally!). The car will not fit in my garage with any useful room around it so I'm pretty much limited to fine days when there is no-one else around and I have opportunity- this I can foresee is going to be a problem.

Anyway there has been slight progress. I realised I wont be able to check much of the motor with a gaping hole in the electrical system so sorting out the various electrical ancilliaries has moved up the priority- also if the worst comes to the worst and I have to bale on the project, then I will at least know what bits work when I sell it for parts!

Anyway I ordered a coil and a washer bottle. The washer bottle arrived- was connected- and didn't work. I traced the wiring from the column to the pump- found no fault so put it back together and hey presto it worked! This it turns out, is going to be a pattern- presumably its a multitude of bad contacts that have built up over the years. However its deeply unsatisfactory- if I find no fault I cant be certain I have fixed it and so that it wont come back again- bummer. All I can do is clean every contact I disconnect in the hope that this might be the problem! There should be some sort of grease you can coat all these bits with to stop this horrible gritty greenish or whitish corrosion from building up on bullets and spades- anyone know?*

*Thank you responder- turns out there are various forms of dielectric grease that should protect as well as lubricate the contacts- I bought a cheapo tub on Ebay and I'm now applying it to all contacts I disconnect/clean as a matter of course. Hopefully this will improve the situation as I move around the car!

Washer bottle in situ- the empty space offended me! Nice to fill it and tidy up at least one loose wire. Need more tubing!

During the process of this fix I had checked the fuse- given the dodgy nature of connections I thought I should remove check and clean them all- which I have now done (Fuse box is under drivers side of dash on right). Sadly I found no missing or blown fuses and replacing them didn't improve anything! Ah well one more job down.

Wipers

The wipers on the car had shown no life since I got the thing. Once more I started tracing the wires- but here it got complicated as I couldnt work out what was what! Turns out the power is fed by green wire to the column switch  but at the same time directly to the wiper motor (terminal 4). This was really puzzling and the motor seemed to have far more connections than it could possibly need! This again is to emerge as a common occurrence. Much thought later and a flash of the blindingly obvious- I eventually worked out that this is for the parking mechanism. Without a direct motor feed the wipers would simply freeze wherever they are when they're turned off! So this means that there are 5 wires going to the column switch from the white under-dash connector: the green is a double wire- (power into switch and also out to motor park system) and the other 4 are power distributed through the switch. My manual contained no diagram for how connections are made inside the switch so here is what I found:

Up position (off) No power output from switch but red/green connected brown/green allowing parking system. 

Down 1 Power to red/green single speed speed wipe

Down 2 Power to blue/green double speed wipe.

According to my wiring diagram the switch is connected to the wiper motor directly- but this isn't so. The switch went into a multiplug connector that attaches to a small black Lucas box 6DA under the dash and not shown on my diagram.

Lucas 6DA controller. White multiplug goes to column, black multiplug to wiper motor

A little research showed that the 6DA (or AAU 7087A) is a single flash wipe/ intermittent wiper control; a surprise as I didn't think this car had such a system. Anyway, contents of the black box are certainly beyond my tinkering although not replacing if it proves faulty.

The wiper motor on this car is located above the passenger's feet behind the dash. The underdash panel is present on this side so I removed it. I had read horrible things about access to this motor in the Excel but surprisingly in this early car it seemed OK to get at. I disconnected the multiplugs and tested to continuity to the black 6DA connector- all fine.

Wiper motor under dash above passenger's footwell. White multiplug connector comes in from lucas 6DA controller.

Carefully I applied a 12v feed directly to the red/green terminal- and hey presto-wiper motion! I tried again to the blue green and got no movement but a very hot wire- my probe wire was too thin and in danger of melting! I have ordered a Sealey PP1 probe to help me apply power to components in position more conveniently (and safely)- will let you know how it works out!
So everything put back together- and yes you guessed it, wipers now work on both speeds although they do not park. The flash wipe also operates but since the parking isn't working the wiper freezes as soon as you release the column. Wiper parking failure seems to be a fairly well known problem on these motors- if my experience is anything to go by then it may well be yet another bad connection. Happy with progress so far- put parking mechanisms on the list to sort out later.