I've been looking around online for a while trying to trace the source of the problem. I have a 98 Coupe 2.2L Auto. The dome light/courtesy light doesn't do anything when the doors are opened OR when the dimmer switch is set to on (on my previous Cavaliers that turned on the dome light when it clicked up past the highest dimming setting. My dash lights and climate control area lights still work normally.

I have checked and replaced the fuse even though it "looked" good just to make sure.
I have bought new bulbs
Switching the dimmer switch to on doesn't turn the lights on


I'm having the same problem with my trunk light. Tried replacing it's bulb with no luck.

To the best of my knowledge the lights worked when I got the car (I can't say for sure though). The car had a very old cd player that I replaced with a new JVC deck with the appropriate wiring harness adapter and such (it had the correct harness before, but a very odd mounting kit which I changed).

I've looked and double checked the stereo harness and everything looks right and all other lights seem to work properly it's just the dome, trunk, and glove box.

I can live with it if it's a huge hassle to track down it's just a pain in the rear end when I'm trying to get something out of the trunk at night, or looking for something inside the car at night I end up using a small flash light I keep in the glove box.

What about the wiring to the lights and voltage to the fuse box it seems like you either aren't getting power to the fuse or from the fuse to the light


2002 Pontiac Sunfire SE Sedan 2.2l Ecotec 4 Speed Auto.

backpacker3 wrote:What about the wiring to the lights and voltage to the fuse box it seems like you either aren't getting power to the fuse or from the fuse to the light

I'll have to dig out my multimeter and see what I get at the fuse, and if I get anything at the socket for the light as the next step I suppose in the troubleshooting process.

Chris Thatcher wrote:

backpacker3 wrote:What about the wiring to the lights and voltage to the fuse box it seems like you either aren't getting power to the fuse or from the fuse to the light

I'll have to dig out my multimeter and see what I get at the fuse, and if I get anything at the socket for the light as the next step I suppose in the troubleshooting process.

Well after digging out my multimeter I'm further confused. I insert the probes to positive and negative on the socket for the bulb. I get 11volts. I flip the polarity of the probes and get -11 volts. To me this would suggest it's getting power to the socket.. So now I'm quite confused. When I close the door it drops to 0 volts. When the door is opened again it goes back to 11 volts. so it knows when the door is open and closed. With the door closed and the dimmer switched clicked all the way to "on" it gets 11 volts regardless of the door open or shut.

I don't see how the actual socket would be bad... Let alone ALL the sockets.

I've tried 4 different brand new bulbs, none light. I tried ordering some LED bulbs from ebay and they lit very dim.. at the time I thought just the bulbs were garbage. Now I'm wondering if somehow the fuse is getting power but not enough for load? I'm not exactly an electrical guy. The battery is a month old and my stereo, speakers, and headlights all work fine.

Decided to do a little test. I connected some wire to the LED bulbs so that I could try connecting them directly to my battery to test that the bulbs themselves were indeed good - they lit up like the sun - was surprised how bright they actually were. So the bulb is good. Okay I then take that same bulb and connect it to my dome light and it looked a lot like a car with a dead battery... barely had any light coming from it. (I imagine a LED uses less power to emit light so it shows some light compared to the conventional bulbs needing more - and not lighting at all.

So with my multimeter saying it's getting 11volts at the socket, is it possible there's an electrical nightmare somewhere else causing it to lose some of the power? Or could there indeed be a problem with the dimmer switch? I thought the switch would have to be good if it worked to dim the gauge cluster lights, but with the evidence I'm seeing now I'm not sure where my next place to check would be.

I have this same issue with a 97 ls cavalier. I spent weeks trying to figure it out without ripping the car apart. Its like the car is missing a ground.




On the inside my car looks like a fighter jet.

Rob Dotterer wrote:I have this same issue with a 97 ls cavalier. I spent weeks trying to figure it out without ripping the car apart. Its like the car is missing a ground.

That's not what I wanted to hear lol I can only imagine any kind of rewiring will be a nightmare.

I guess the only way to really determine would be to work my way back from the socket since the socket is getting power. I could try using the power from the socket and grounding elsewhere and see if that's a problem of a broken ground... obviously that wouldn't be too hard to fix but it'd leave me to believe other things are being affected than just the bulbs if a ground is bad. I had also though about taking the dimmer switch out and connecting the test leads for the LED directly to the output of the dimmer switch..

I hate electrical troubleshooting It can take hours to find some tiny problem.

Double check the grey (illumination) wire you connected to your new deck. It directly connects to the interior (dimming) lights circuit.

The 97 had this issue with a factory deck. I hope someone figured it out.




On the inside my car looks like a fighter jet.

I'm grasping at straws here but I had a somewhat similar situation, with my hard-wired radar detector. It stopped working in one of my cars one day but when I measured the voltage at the wiring connector, it was pretty good-- like 10V, but not the full 12V-13V that you'd expect with a good, fully charged battery. You mentioned that the light socket voltage reading was 11V, not 12V-13V ( which would be more typical for a properly working battery). If the reading at the battery (or cigarette lighter) is 12-13V and the light socket is only 11V, that would tend to indicate that a wire or connection went bad (probably from corrosion). If so, the reason would be this... When there's no resistive load on the circuit (i.e. no light bulb) then the weak (let's call it thin or corroded) connection CAN carry enough current (amperage) to make the volt-ohm meter read a pretty good voltage (11V) because volt-ohm meters draws very little current, but once a resistive load (i.e. light-bulb) is applied, then the weak/corroded wire CAN'T carry enough current, and so the voltage drops.

In the case of my radar detector, I had hard-wired it about 6 years prior to it failing, using a copper-wire phone cord since the radar detector has a standard RJ-11 phone jack) for its power supply. My volt-ohm meter showed that the voltage reading at the RJ-11 connector was slightly lower (~10V) than the voltage at the fuse box where I had cut off the RJ-11 connector and connected the bare wires to a power lead. (I would think that 10V is enough to drive a radar detector but I doubt that the voltage at the connector remained at 10V once the radar detector started drawing current.) I tried clipping the end of the wire and re-doing the wire connection but that didn't help because (apparently) the wire had gone bad (which is hard to believe since it's copper and doesn't have to endure any physical stress). Once I put in a new phone cord wire, it worked perfectly and read exactly the same voltage at the plug as at the fuse box (~13V).

In the case of your car, I think it's more likely that a connection went bad than a wire. To debug, I'd try to trace the wires back from the socket towards the fuse box and test the voltage to see if, at some point the voltage increases to 12-13V. If so, the problem is somewhere in between so I'd probably try to redo the connections.

The other possibility is that the switch or relay is failing. Again, I'd trace it back until I got 12-13V, and consider replacing anything in between.

I'll bet the portion of your BCM that controls the interior lights, (glove box and trunk light are also in the series), is fried.
Have this same issue with my '02... with mine, I suspect the car was not grounded properly at the muffler shop when they welded in a new flex coupling.
I've already bought a new "vanilla" BCM and plugged it in, and the lighting problem was resolved, but without re-flash the car will not start, because Passlock.
For what it's worth.






I'm a 6ft. tall, 250+ lb., man, and I proudly drive the Sunfire. My wife drives the half-ton 4x4...

Considering neither of our cars had a bcm I doubt it. I ended up running the dome light to th door switch manually on the drivers side to make it work. I gave up trying to fix it. I d ripped most of the car apart. Had ground and power everywhere but the bulbs wouldn't light. Made zero sense. Almost as if the current wasn't strong enough.




On the inside my car looks like a fighter jet.

What about the bulb sockets? Could be a bad wire inside


ReD RaiN