My left tail light running light (small bulb second over from far left) won't come on and I get a tail light indicator on the dash. The car is an 82 Euro 928S. The housing was cracked so i bought a used one in good shape. When the new one is plugged in the same bulb does not work. I even tried an extra housing I had with the same results. All other lights in the assembly work except the running light. I tested the wires at the plug with a meter and I have power on the car side but as soon as the connections touch in the plugs to each other the power reads zero. All connections are clean and fuses are checked. Is it a problem with the bulb computer under the driver side of the dash? Alan are you there? Gunar

 

It is likely a contact resistance build up issue - clean all the connectors you can reach (including the bulb holder) lamp connector & inline connectors carefully and use deoxit or similar on them, before reassembly.

Do clean all the grounds too.

It is most likely in the hatch area since that often gets wet which promotes corrosion.

Alan

 

Do all of your other exterior lights work (especially other lights in same category)? I had a few out in the beginning that came on as I replaced bulbs- example: left rear (not side) parking light and front right (not side) parking light. I replaced bulb in rear, front started working. Never did trace this in WSMs/WDs though to see if it was really happening and not just "observed behavior" though...

 

I will check

 

+1 to what Alan says.

You might also check to ensure that all of the pin sockets (female) in the harness plug are actually engaging all of the male plug pins on the tail light assembly plug. In other words, try to ensure that none of the female sockets are pushed too far into the harness plug to make good contact with the male plug pins when they are connected.

That was one issue I encountered, along with some barely noticeable corrosion inside the pin sockets. Pulled out one socket that was too far recessed into the plug and cleaned all of the female sockets with a very small rat tail file and CRC, and also cleaned each of the male pins with a small "points" file and CRC. That cured the problem which was slightly different than your symptom.

Tail Light Error
https://rennlist.com/forums/928-foru...long-post.html

 

I think this is my problem after checking continuity and powering all the tail lights on with power wire I connected to license plate light positive. I have deoxit and am trying to remove the pins from the plug to clean them up. I am thinking about getting rid of the plug if I have to and wiring directly

 

Bypassing the plug still won't work. The tail light positive reads 11.5 on meter yet when I touch it to positive on light it won't light The same light turns on when I touch a positive to it from tag light and with the same ground. Could it be a relay?

 

Have you checked fuses? On my 89 year Left and Right lights have separate fuses.

I hate electrical gremlins.

 

Yes I have continuity through the fuse. The old tail light assembly was so broken it might have been causing a short. I see some brown discoloration around the fuse on the elelectric panel. I am going to pull it down and look at the wires behind it tonight

 

Everything looked great behind ce panel. I gave up on the left tail light circuit and patched into the right. I hope it doesn't give me any problems but for now all lights are working as they should

 

Patching into the working right running light was not the answer due to warning indicators staying on so I did more research. I removed and cleaned the bulb controller above the ce panel and that fixed the problem. Thanks for the help.