Hello diesel brethren,

You may have noticed that I recently updated my signature to reflect that fact that my W201 (190D) is back on the road. I had gotten the delivery valve seals and injectors replaced, but got stuck on a clutch hydraulic problem (ended up taking it to Burback Motors for repair, which they did competently).

However, it had sat for quite a while , and now that I'm driving it again I have encountered some electrical gremlins that show up primarily as the following: I get in, turn the key to glow, all the proper status lights and glow plug lamps light. Wait the prescribed interval, then engage the starter. Car starts normally. After driving for about 5 to 10 minutes, the engine continues to run, but the light with the battery symbol will come on. Once this happens the turn signals stop working. Sometimes I have noticed that applying the brakes will trigger the condition with the battery charge warning lamp: if I press on the brake the lamp will come on, or if the lamp is already on it will glow more brightly while my foot is on the brake. I'm worried that the brake lights are no longer working when the lamp comes on, but I haven't had a second person with me in the car yet to test whether that is true. If I wait long enough, like 20 minutes or more of driving, the lamp will go out and everything is normal for as long as I care to drive.

Most of the other electrical items of the car continue to work when the battery lamp comes on: I've tested and found the following all work even when the lamp is lit:

- interior light
- windshield wipers
- front headlights and side markers
- the fuel gauge continues to work, though I sometimes see it whipping around like there is an open in the circuit somewhere (I've taken the sender out and cleaned it - though it was clean as a whistle to start with)
- the temperature gauge continues to work normally
- the interior fan works normally
- strangely enough, the emergency flasher will work when the lamp is on, even though the turn signals will not!

So far, here is what I have done to try and correct the problem:

- replaced nearly all the fuses, which were aluminum, with the better copper ones; I still have a couple at the top of the tray left to do (ran out of fuses)
- cleaned and re-tightened the clamps on both battery terminals, as well as the ground cable connection from the battery to frame
- the tech at Burback said that he looked at the alternator brushes, and they were good, though the commutator looked a bit corroded.

I did see some flakiness once with the ignition switch: I went to start it, and the lights all went out until I turned it back to off, and then turned it back on. This happened a couple times, so it seems like the electrical portion of the ignition switch probably needs replacing. Does it seem possible that this could be the main problem?

Other possible causes:

- some other frame ground strap is high impedance, needs to be cleaned and tightened?
- the alternator and/or voltage regulator really is bad, needs to be replaced?
- the turn signal relay is bad? (Where is it?)
- there is corrosion on some of the connections behind the dash?

Any advice on how to tackle this?

Thanks,

Kurt

__________________
- '79 240D - engine swap complete! Engine broken in! 28-31 mpg! Lovin' the ride!
- '86 190D (W201-126) - 2.5 NA engine, 5 speed, cloth interior, manual climate controls, 33-34 mpg (sold to forum member).