Interior Ceiling Light

Yesterday Evening I noticed my interior ceiling light was on.

Checked manual (no troubleshooting options).

Checked fuse box list (no choise for ceiling light only dashboard lights.

As soon as I began to drive the light went off.

When I parked the car the light went back on.

CChecked all the doors (closed).

Checked all the door buttons and light went off on all 4 doors when I pressed the buttons.

Can you tell me why the light stays on when parked?

Removed bulb to prevent battery wear.

You didn’t say you checked the dimmer switch position to see if it was on.

The jamb switch should be part of the latch. Spray PB Blast into the latch and it might help.

Yes, I did make certain the dimmer switch was off for ceiling light.
I even lowered it to the max. to see if that would help.

I think the lead from the positive side of the battery through the fuse panel to the ceiling light is always hot. The switches at the doors complete the circuit to the frame of the car (the ground) which is attached to the negative cable. The first suspect is one of the door switches. Another possible problem may be that the ceiling fixture itself is not insulated from the body of the car. With the bulb installed, try wiggling the ceiling light with the doors closed and see if the light goes on and off.
A cheap fix would be to put a switch in the hot line going to the ceiling light. However, with the switch off, the light won’t come one when a door is opened, but bottom of the line cars didn’t have interior lights that came on with the opening of a door. My bottom of the line 1965 Rambler Classic 550 didn’t have door switches.

After looking at this again I have to wonder about a statement you made and one of the suggestions from Triedaq. You stated you pushed on the door switches and the light went out on all the doors. This would seem to indicate the door switches are ok unless one of them didn’t turn the light out when pushed in. I have to wonder if there may be a lighting control module that is programmed to turn on the light when the shifter is in the Park position. Since the light turns off when not in the Park position I now suspect this may be the case.

Thanks to all of you who offered some very good ideas.
After performing a diagnostic test on the electronics, it ended up being rust buildup on the back of the jam switch. After spraying and pulling the switch out slightly for better contact, the problem was solved.

Good deal. Glad you found the trouble and thanks for the feedback.