In my 69 Cutlass conv. my interior light underneath the dash are always on. I can't turn them off, and they already killed my battery. Where would you start hunting down the problem.

 

Tom, first make sure the courtesy lights aren't turned on at the headlight switch. See if you can turn the headlight **** toward the driver side of the car. If you can, and feel a slight detent as you turn it, that isn't the cause. If you can turn it towards the passenger side of the car and they go off, problem solved.

If car has a map light above the radio, operate its switch and see if it affects the under dash lights.

If these switches check good, then check the adjustment of the dome light pin switches in the door jamb areas. They can be screwed in or out a little as needed to turn off the dome lights. If you've recently installed new weather seals, this could be the cause.

Last, you may have a shorted wire in the dome light circuit but that should blow the fuse. The power feed wire to the courtesy light switches is orange, the ground side wire is white. One of the white wires may be making ground and keeping the lights on.

 

Did this issue ever get solved ? I have the same problem and even changed out light switch and there still on ??

 

No, I didn't have time to hunt the problem down. After I followed the tips of rocketraider which unfortunately didn't help, I just took out the bulbs and I was going to do it once I have a electric meter and the harness blueprint out of the service manual. By next week I maybe know a little more.

Tom

 

Ohh after rereading I think I have a different problem. My actual dash lights are the drainer- Im also waiting for my manual to save the day and many others.

 

In the absence of there being a problem with the headlight switch and incorporated dash panel lighting dimmer the issue pretty much gets down to any light socket having both power and ground wires. Are any of the exterior lights, such as side marker lights also on or even glowing slightly though the headlight switch is in an off position? I would also check the brake light switch and any other switch where a ground feedback could occur.