right tail light ground location

[Ron Dame]

Where is it? My right tail light acts up whenever the headlights are on. My first step is ground checks, but where does the white ground lead? It goes up into the body, but I have no idea where it exits and grounds.

Thanks!

[AD]

Ron, 

I believe that this wire runs all the way to the front of the car and might ground somewhere behind the dashboard. On the wiring print it looks like it ties in with the ground for the fuel gauge. Have you tried running a jumper wire from the lamp socket to ground and seeing what happens? If you do this and things act normally perhaps consider just running a new ground wire from the lamp socket and attach it at one of the body mount bolts in the trunk. 

[Ron Dame]

19 hours ago, AD said:

Ron, 

I believe that this wire runs all the way to the front of the car and might ground somewhere behind the dashboard. On the wiring print it looks like it ties in with the ground for the fuel gauge. Have you tried running a jumper wire from the lamp socket to ground and seeing what happens? If you do this and things act normally perhaps consider just running a new ground wire from the lamp socket and attach it at one of the body mount bolts in the trunk. 

I have tried grounding it to the other tail light, which works normally, but no change. Bez also indicates that the grounds end up  in that general location. I don't think I had this problem before I had some front paint work done, but will check my grounds there. The odd thing is that If I move the rear socket around, all is OK.. for a little while. And it only happens with teh headlights on.

[ronmanfredi]

56 minutes ago, Ron Dame said:

I have tried grounding it to the other tail light, which works normally, but no change. Bez also indicates that the grounds end up  in that general location. I don't think I had this problem before I had some front paint work done, but will check my grounds there. The odd thing is that If I move the rear socket around, all is OK.. for a little while. And it only happens with teh headlights on.

You already answered your own question.  The bulb socket or ground wire connection is more than likely the culprit.  If you have an ohm meter or continuity tester, you can connect it to the ground wire on both tail lights to confirm the ground wire is good, then you can focus on the socket/ground wire.

 

Edited September 10, 2023 by ronmanfredi

[AD]

Ron, I think you have found a good clue. Make sure that the inside of the lamp socket is clean and shiny. I think on a lot of these the ground wire was soldered to the base of the socket so check that too to make sure it's not failing. You might also try a different bulb just to rule it out. Good luck and let us know what you find.