I have a 1970 Toronado. All was fine until one day I closed the door and the interior lights stayed on in the doors and rear sail panels. The 2 underdash lights did shut off. I checked door jamb switches and they seemed good. The lights get slightly dimmer when I shut the door, but still stay on. I then pulled the headlight switch and unplugged it. No change, lights still stay on. Checked glovebox switch and the light. No change. I started looking for shorts in the white wire. No luck. Any ideas? ??

 

Keep looking for that short in the white wire. That is the only possible cause, especially since you eliminated the contacts in the headlight switch as a possibility.

 

The 2 lights under the dash go out. Am I correct in assuming they have a different power source? Should I be digging in the doors or roof?

 

The interior lights should all be on the same circuit.

 

All interior lights get power from the same orange wire circuit. The two under-dash lights have a different GROUND wire - a white with black stripe. All other interior lights (overhead dome, doors, and rear quarter lamps) get ground from the solid white wire.



The door switches have two contacts (three on the driver's door - the third one is for the key buzzer). One contact switches the white wire and one switches the white with black stripe wire. The latter is working correctly. The former is the problem. Did you pull the wires off the door switches to verify the problem isn't there? Failing that, the short could be anywhere in the white wire circuit.



By the way, there is a diagram and troubleshooting flow chart on page 12-58 of your Chassis Service Manual.

 

The under-dash lights are not on the same ground circuit, as shown in the CSM.

 

I don't have the manual. The pass side door never turned the interior lights on so I figured it wasn't the problem. The drivers side does shut off the lights under the dash so if it was shorted I figured it wouldn't turn off just 2 of the lights.

What else does the circut to the doors power? Could something else be shorted on that circuit?

 

There are 2 switches in the door jamb on drivers side. The top switch has both the solid white AND the striped white wire so the problem can't be the switch since it does turn off the 2 lights under the dash, right?

 

No. The switches have separate contacts for the general interior lights and the under dash lights. One can short without effecting the other.

 

No. Both wires together in plug. When pulling the switch out it rotates. Same contact for both.

Fixed. Not switch related.

Thanks for the help.

 

What was it?