Need help trouble shooting electrical problem with the courtesy lights. When I bought my car, there were no bulbs in the under dash courtesy light sockets. I put a bulb in the passenger side light socket (attached to kick panel), and this light and the courtesy light under the rear window area functioned fine: doors open, lights on and doors closed lights off. Also the light switch on the dash operates these two lights fine. When I put a bulb in the driver's side under the dash, all three courtesy lights remain on with doors open or closed. Is the socket faulty? Any help would be appreciated. Thanks in advance.

 

The courtesy lights should have power to them at all times, but only turn on when either of the door switches or headlight switch provides a connection to 'ground'. I'm guessing that the non-hot wire on the drivers side light socket is somehow touching a ground point someplace before it gets to the door switch/headlight switch. It could be a frayed wire, or some bubba wiring. The socket is fine if the bulb lights up.

If you have a multi-meter (volt meter/continuity tester) you can verify this by doing the following. Remove the bulb, and verify that one of the socket wires has 12 volts on it. Now, see if the 'other' wire has a connection to ground (make sure your doors are both shut & headlight switch is off). It should not be connected to ground, and if it is, you need to find out why.

 

Make sure the bulb and the socket are the correct type. You didn't say what year car you have, but on an older car if you put in a bulb with one contact (instead of the two contacts on the bottom of the base) it shorts across the two contacts and causes the ground to make through the filaments to the base. With the courtesy circuit, you don't want a ground on the socket mount, only to the ground wire that comes out and goes to the door switch.
Try taking the socket loose from it's mount to see if it's grounding internally to the metal bulb holder part. Also look inside with the bulb out and see if some small wire has fallen into the socket, or if the metal contact that touches the contact on the bulb is against the side of the socket. It does sound like the socket is causing the problem. If it was in the door switch, the passenger side light should be staying on even without a bulb in the driver's socket, since the switch operates both lamps at the same time. Something in that bulb or socket is providing a ground to the courtesy circuit when it shouldn't.

PS: You should always state the year of the car in your question, or at a minimum fill out your profile with the car info.

 

Like Jack said-

If it's a 78 or newer there's a Courtesy Light Timer that would cause this problem.

 

Depending on the year of your car, doesn't the D/S switch have a wire going to the timer for the courtesy interior lights..? IF so maybe it's the timer and that's why the previous owner removed the lamp from the socket?.Jim

 

Say year!
If your car had a interior light delay, bypass it and keep interior lamps like every other car. On & off with headlight switch or by door pins. I just did it on my 77. No more dead batteries or waiting at car to make sure they go off.
Jax
77 L-82

 

The delay timer on my 81 was faulty, but I liked the timer. Decided to repair it myself cost be about $3. It no longer dims from on to off, but that's fine since I'm using LEDs now. Best thing is the part I replaced that controls the lights is now rated to over 100A (at least that's what the spec sheet said, I'm not that optimistic) so should last a very long time.

 

Thanks for the advice. Sorry about forgetting to include the year: it is model year 1972 which does not have a timer or delay. After first using the wrong bulb, I did purchase the correct bulbs which illuminated. Going to try to tackle this problem on the weekend.