Slight burnt plastic smell and dash lights on - PeachParts Mercedes-Benz Forum

trt · #1 07-30-2010, 04:46 PM

81 300D turbo. Still drives fairly normally. I think the vacuum is affected as doors did not lock when I locked the driver's side door.

Jeremy5848 · #2 07-30-2010, 04:48 PM

In your refrigerator or your stove or what?

trt · #3 07-30-2010, 04:52 PM

:-) edit.

Jeremy5848 · #4 07-30-2010, 08:05 PM

Your car has a pure vacuum central locking system so it should not be affected by electrical problems unless something burned up and melted a connection. Do you mean that the row of warning lights at the bottom of the instrument cluster are on all the time or are you talking about the lights that illuminate the dials? If the former, the row of warning lights, they are powered up in test mode when you first turn on the ignition switch in pre-glow.

If something went wrong with the ignition switch, it could light those lights all the time and also damage the vacuum shut-off of the engine, which would also affect the vacuum to the doors. You say the car seems to run normally, I assume that means it shuts off normally? That would rule out my hypothesis.

Vacuum is also used for the climate control and the transmission. If the only thing that doesn't work is the door locks then I am stumped.

If there are any other symptoms you can tell us about it would really help us to help you. And please add your car to your signature (use the "User Command Post") so we don't have to ask.

Jeremy

layback40 · #5 07-30-2010, 08:28 PM

Some after market dash globes are higher wattage & can cause plastic bits to get hot. the heater fan knob is an example.
Sounds like you have a vacuum leak in the central locking system that is causing your door lock problem. It may be a hose off inside the drivers door.

trt · #6 07-30-2010, 11:24 PM

3 warning lights except the far left are all on and remain on.

The vacuum to the doors actually worked today though it'll only work a short while after the car is turned off.

Actually it does not quite shut off normally. It will diesel for a short while (if it was on for only a short period of time) but this was the case before this situation.

Fan works but a/c does not. Transmission seems normal.

Quote:

Originally Posted by Jeremy5848

Your car has a pure vacuum central locking system so it should not be affected by electrical problems unless something burned up and melted a connection. Do you mean that the row of warning lights at the bottom of the instrument cluster are on all the time or are you talking about the lights that illuminate the dials? If the former, the row of warning lights, they are powered up in test mode when you first turn on the ignition switch in pre-glow.

If something went wrong with the ignition switch, it could light those lights all the time and also damage the vacuum shut-off of the engine, which would also affect the vacuum to the doors. You say the car seems to run normally, I assume that means it shuts off normally? That would rule out my hypothesis.

Vacuum is also used for the climate control and the transmission. If the only thing that doesn't work is the door locks then I am stumped.

If there are any other symptoms you can tell us about it would really help us to help you. And please add your car to your signature (use the "User Command Post") so we don't have to ask.

Jeremy

trt · #7 07-31-2010, 03:24 PM

Took it to a shop. It seems that the alternator failed. Was offered a reconditioned or new with a recommendation for a new for about $300.

Tech could not smell the plastic burning smell, however he did not drive it. I noticed it after driving it a little.