Hello 2CV Friends, I really hope the wise experienced gurus here can point me in the right direction.
I'm struggeling with an electrical problem on my Danish spec '87 Club.
It all started today. I had been driving only a few 100 meters when I noticed that the blue full beam light was fading in and out when I revved the engine. I was driving on dipped beam.
I took it back to the garage and started to investigate.
With light switch turned on, I carefully lifted the main cable bundle, which caused a relay to click. That was when I learned that the car was supposed to have automatic driving lights. That arrangement has never worked.
It seems to be something like the UK Dim-Dip arrangement, except I don't have the resistor on the chassis, and I have one diode in the fuse box, and one on one of the relays.
I removed the tape from the cable bundle and found that the ground cables were falling apart at the clamp. Repaired that, removed the two relays and disconnected the diode in the fuse box.

Now the car will not start. When I turn on the ignition, my oil pressure light flashes bright and then dims to a glow, gradually fading in to normal. Most of the times, when I turn the key to start everything goes dark and nothing else happens. When I release the key, my oil pressure light turns on again. Sometimes the light flickers when I try to start.
My ignition switch is new. I have tested and get 12,6 V on the starter pin, but 0V on the starter terminal. However, measuring resistance in the wire gives me 0,02, which should mean the wire is ok.

I fear I have a short somewhere, but where should I start, and how can I best troubleshoot this?

is your starter motor ok? Seems that it takes all power away. Or the battery might be bad?

I thought my starter motor was OK, at least it worked fine until I started fiddeling with the ights. I will of course test it. The battery should also be good, showing no signs of weakness before, and it is only a couple of years old.

I suspect that I am dealing with at least two different problems at once, with the lights all weird probably because of broken ground wiring, a broken diode and a fishy relay. What I cannot get my head around is that this should cause the problems with the starter.

Check your battery connections and clean your earth points at the gearbox and on the bulkhead, as any poor connections at these will have an effect on your electrics Fault tracing has to be methodical or wise you waste so much,time, a must is the use of a multimeter, it'll be the net few quid you,be spent

Thanks for the advice. I am still pursueing it as two separate problems, taking care of the problems with the headlamps first. My ground connection points seem to be ok, but just to be sure I'll be renewing some of the wires while I'm at it. I'll keep you posted when I learn something significant

I finally figured everything out. Have spent several hours and tens of metres of tape, but now everything is working again.
I cannot point to the one single thing that solved my problem, as I did quite a lot while I was at it.
I know from measuring that the diode in the fuse box was faulty, so I removed that. I also removed the whole relay kit for my heated rear window, as that socket was badly burnt. Then, I proceeded to remove the DRL relay, and rewired the dip beam wires through a new fuse box. I also inspected every wire in the main cable tree from the light rack all the way trough the engine bay. There I found several damaged joins, which I replaced.
I also replaced the main wires from the battery to the starter and gear box, and replaced the ground wires to the body.

I guess the moral is: 30 years leaves its marks on copper and plastic. I was lucky, the broken wires did not cause a fire, but I fear the thought of what would have happened if I had not noticed this before leaving for a meeting this weekend. Too bad I missed the meeting, though.. :/

I had a similar coincidence with my Trabant 601. Could very well be the battery cables.

I pulled the engine/transmission out to fix the 4th gear freewheel and after putting the drive train back in, I was out test driving it, so it stopped at my parents house to chit chat, came out and the car would not hit a lick. Starter initially spins, then all circuits went dead. Even the interior light!

Battery was strong at 6.4 volts (it's a 6 volt model). Battery cables showed no resistance with my meter.

How can removing the drive train cause this to happen? Well apparently nothing.

When I got this car, the battery terminals looked groaty so I replaced them with these steel plated units. After a couple of years they started to corrode.

http://i222.photobucket.com/albums/dd14 ... knthpi.jpg

I ended up replacing both cables with new ones with lead connectors. The result:

1) Starter spins faster and does not require ether at temperatures below 0C.
2) Tickover speed no longer wanders. I installed a 60 amp/6 volt GM alternator that produces twice the current as the original generator so it pulls some engine power.

The engine is still a pig to start in the summer on hot starts when it's 34C....

Eventually I'm going to install new cables on my 2CV simply because of what happened with my Trabant.

don't repair what isn't broken,,,