Series 3 Wipers dead, temp gauge dead, fuel gauge dead

So, an interesting problem occurs intermittently with my 1977 88" SWB diesel. My wipers suddenly stop working (including the windscreen washer pump), together with the temp gauge and the fuel gauge. This is not much of a problem when it isn't raining, but when it is, and when you're cruising down the dual carriageway at the incredible speed of 60 km/h, it can be something of a nuisance. So far, I have stopped the car, turned off everything, waited for a little while, and hey presto - it works again.

Today, when it happened again, I also noticed that the tail lights had stopped working, possibly at the same time, but when I fiddled with one of the connectors for the tail lights, it came alive again. The tail lights are possibly not an associated problem, so I just mention it "en passant" as our French friends put it.

In any case - what am I dealing with here? An earth strap problem? A voltage stabiliser problem? Gremlins in the alternator? Any ideas are more than welcome! The rear harness has been swapped for some homemade stuff by one of the previous owners, so it will be replaced in due time. Until then, I just want the stuff to work... I have been studying the circuit diagram for quite some time, but do not seem to be able to pinpoint the culprit here.

While at it, can someone tell me the article numbers for:

1. The voltage stabiliser unit
2. The earth strap from the alternator to the chassis
3. The earth strap from the starter motor to the chassis

I've got the green bible and the parts catalogue, but they do not guide me on this issue (read: I do not find anything about it). Over to you, fellow wizards!

I had the same list of problems on my 90 tdi 300. There were a number of causes. Water in the relay, fuse not seated properly, water in rear indicator lens, faulty indicator switch (runs off same fuse as gauges). Just work your way through connections with wd40 and emery board.

Fuse not connecting a common problem.

Sofasurfer and tottot have covered it I think.

The fuse for the fuel and temp gauges is the same one as the brake lights, and the fuse next to that is wipers and indicators - so have those passing French nobbled your flashers too? If so, fuse holder again. They really are rubbish, and you'll just need to remove the fuse and bend the contacts slightly. Don't overdo it or you'll weaken them too much.

Its probably the ignition fuse and at the same time you lost the wiper's and stuff you probably lost ignition aswell but as yours is diesel you probably wouldn't have noticed that as the engine doesn't have a fuel solenoid like later diesels do now, hope you sort it

Thanks, oh wise people! Some WD40 and sandpaper later, everything works fine

Might be useful in the future. For an S3 petrol 2.25l.

This one:

Gently using pliers nip the fuse holders together. They can get quite loose. Careful not to damage the springs/ holder.

Georgeblade said:

Might be useful in the future. For an S3 petrol 2.25l.

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This one is for the military model.

Col

Thanks! I got the green bible and the spare parts catalogue, so I am okay as far as wiring diagrams go. Thanks anyway, next year's project will be to swap the rear harness... some previous owner changed the original one for domestic electric cables and I am keen to sort that.

Thanks, very timely thread as my S3 temp and fuel gauges have been erratic for a while and having tapped the glass today now don't work so voltage unit appears either open circuit defective or disconnected. Wipers and washer both work so not the fuse

Went to start the vehicle this morning, newish battery completely flat with 2V across terminals. So something shorted behind the dash probably, but not high current as no burnt smell. Anyone else had this please?

David1974 said:

Went to start the vehicle this morning, newish battery completely flat with 2V across terminals. So something shorted behind the dash probably, but not high current as no burnt smell. Anyone else had this please?

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Are you using one of those big red isolator switches if so check it as mine got wet after off roading when I had the 90 and the battery was reading similar to yours, removed the two cables from the switch and joined them together with a nut and bolt and taped it all up sorted till I replaced and moved the isolator switch

Steamwally discovered an interesting problem that might be worth taking into consideration, 6.42 into the video. It does not seem related to water problems at first, but he explains the connection in this video (at 0.14). In short, the wiper motor socket can be a trap that you do not think about until you decide to rip half the cab into pieces.