Interior Lights - Shorted Ground

[jgme]

My interior lights started staying on all the time but they are dim. They do turn on bright with the doors open or the dimmer switch turned on. The ground circuit seems to have a short but with some resistance. I've checked the more typical failure points including the door jamb switches and the dimmer switch. I've disconnected each one with no change in status. By disconnecting the connector, C209, I confirmed that the circuit for the footwell lights is not the culprit. Also, I checked the resistance of the dome light circuit at the C453 connector. The short seems to be between the door jamb switches and the connector C453. I moved the wires around near the door jamb switches with no changes in the light intensity. So, the failed point is not near the switches. Would anyone have an idea as to where the white grounding wire may become shorted?

 

[jgme]

Yes, I did search the archives. Also, I did a search with google using the usual Boolean operators and looking for the Regal, Grand Prix, Malibu, Monte Carlo, etc.

 

[garyk1970]

Most common fix is removing the drivers sun visor and moving the white dome light wire....whenever the headliner is done you have to be carefull not to screw into the wires.also check up the drivers a pillar.

 

[jgme]

Thanks. The dome light circuit checked out from the light fixture to the C453 connector under the dash. The white ground wire is not shorted to the chassis. The vanity mirror is unlikely to cause this type of problem. Yes, it has the same power source but it completes the circuit with a local ground near the vanity mirror lights. I've been able to isolate the short to the white ground wires that run between the door jamb switches, through the S320 connection, to the C209 connector (side of fuse block), and to the C453 connector (above fuse block). From memory, it has a 10 ohm resistance between the terminal at the C453 connector and the chassis. Also, as noted, the door jamb switches seem to be functioning properly with no shorts. Again, thanks, as those can be potential problem areas.

 

[garyk1970]

I missed that.....is there any aftermarket keyless or alarm in the car? Some have dome light surveillance.

 

[jgme]

Thanks. Now, there's a possibility. I installed one when the car was new. It's been 24 years. I'll have to check how it was tapped in.

I missed that.....is there any aftermarket keyless or alarm in the car? Some have dome light surveillance.

 

[garyk1970]

Im not sure an alarm that old had that feature...inspect the harness from drivers to passenger side.the white wire is grounded out somewhere .....look for a screw or a chafed harness....pull both floor lights out.look behind radio.t-top car?

Thumbs down icon by mistake...

 

[jasjamz]

Now I have this same issue with a t top car....if it isn't one thing, it's another

 

[jgme]

Well, it took me long enough to get back to this. A move and house work got in the way. I just pulled the interior light bulbs out until recently. Garyk1970 was correct. Finally, I pulled out the old Crimestopper alarm system. That did the trick. No more dimly lit interior lights. The unit must have a component slowly breaking down providing a short to ground with some resistance. It has a circuit that taps the interior lights to check for any doors being opened. Thank you for the input.