I have an LED dome light that I would like to install, however the door switch seems to have no effect on it. It stays on 100% of the time when put into the factory dome light location.

The incandescent bulb operates just fine. I suspect there is just enough ground somewhere for the LED bulb to make use of and illuminate. Any ideas how to mitigate that?

Check it with a volt meter or try the LED bulb straight to a 12v source and see what happens when you disconnect it. Maybe something in it is retaining power like a capacitor does. If it is some sort of low voltage leak that's getting through have a look at the dome light to see if there is any way it could ground and try disconnecting the door switches. Maybe it's only one spot causing the problem.

Does this car have power door locks? Some Mopars share circuitry between the dome lamp and door locks. Paul

Dumb question but have you tried reversing the bulb.

I would put a meter in place of the bulb and see what voltage you get with the switch open (door closed). You should have 0V. If you have 12V, I would suspect you have a small amount of current leaking by, which may be enough to light the LED but not a normal bulb. Headlamp switch would be my suspect (has a dome on position). But tracing the entire circuit would be best.

What year model etc. Most of the 60-70"s cars used a dual contact bulb and the door switches as a ground to complete the circuit to the second contact.
Battery power was present at the positive contact all the time.

Might also want to check the orientation of the contacts to the side pegs between bulbs. If they are off it could cause a short between the contacts.

you do have the interior light off on the headlight switch

there are quite a few LED's out there that are polarity specific. i ran into that just the other day with a third brake light setup.
it sounds goofy, but before you start anything, just turn bulb 180* and re-insert.
not saying this will work, but it has for me plenty of times with LED's.

The normal on led bulbs is they are polarity specific... indeed they are diodes.

if its turning on, is indeed on correct polarity, JUST maybe is not using the correct led bulb replacement.

asuming is an old Mopar which uses the 1004 bulb, needs to be sure you are getting the correct bulb replacement with filaments/emissors isolated from socket and just getting both poles throught the contacts on base. NOT ANY 2 CONTACTS BULB WILL WORK!!! 1057 bulbs for example seems to work being dual contacts BUT NOT! they get ground by the socket and the socket on dome light is attached to the body, so ANY of the contacts getting positive will make it light up and won't turn off ever being, as described previouslly, the dome light is switched on/off via negative/Ground and positive being constant from batt!

you are correct nacho ! i FORGOT about the ground circuit being in the bulb socket. [oldtimer's disease AGAIN !]
so now, it's time to find out where the power is coming from.
it is possible the contact inside the socket is twisting when the bulb is being inserted, or possibly the headlight switch is shorted internally ?

If your car has a light timer on the dome light that can cause the light staying on with the LED, because the led does not put enough load on the circuit to heat up the timer.

What vehicle is this happening on? I put LED bulbs on the interior of my 14 Ram. Every bulb stays on all the time. They are very very dim but they do stay on. In my case, I think the computer continuously checks to see if the bulbs have continuity and aren't blown. If it senses a bulb is out, it sends a message to the gauge cluster. The amount of power sent through the bulbs is so small that a regular bulb would never turn on. Since LEDs require only a fraction of the power to work, they are always on.

It doesn't seem to affect anything on the truck though. I've let it sit for a month and it still starts right up.

If you put a single-contact bulb in a IOD powered dual-contact socket, the light will stay on continuously. (grounds through the socket instead of the door switch)

Re-reading the first post, if this is a whole new dome light and not just the bulb you've change have a look at it and see how it's wired. Maybe one of the screws that holds it in place is also grounding it like a normal socket. I think this all comes down to how that new dome light actually works.

you will have to solder in a resistor to the bulb for it to turn off, had to do it to my 2004 dodge ram after adding some ebay led dome lights.

Thanks for all of the replies!

Car: 72 challenger, no power locks, no dome light timer.

This bulb is apparently a direct fit for my original 1004 bulb, the locking posts and bulb pins align with the old bulb.

The pins on the LED do not have continuity with the bulb base, at least what i can measure.


I haven't had a chance to get back in the car to measure anything else just yet.

I have a LED dome light (just replacement bulb) that will still come on once or twice with the battery (ground side) disconnected. It's faint and if I close and reopen the door it will stay completely out. It does work normally otherwise though. I will try reversing it.

I had a problem with the LED dome light in my 69 RR. Your light is staying on. Mine blew a fuse and toasted my dimmer switch. Turned out it was a problem with the bulb.

See this link here, next to the bottom post; LED

Hope you get yours figured out.

I tried to put an LED in mine and had the same problem you are experiencing. Nacho is correct. The bulb shouldn't derive its ground through the bulb base, but the LED was getting its ground through the base and therefore wouldn't turn off when the door switch interrupted the ground that goes to the one terminal on the bulb.