rooster91

Hey All,
Unfortunately I haven't put the miles on the car this summer so it has been doing some sitting. I went out a couple of weeks ago to go for a ride and the battery was dead. It had been sitting about 3 weeks since the last time I drove it.

This is a 99 and what I found is that all of the interior lights are staying on and not shutting off. I am referring to all of the interior lights, the rear view map lights, kick panel lights and the lights in the hatch area. I cycled the doors and hatch, each time I open them I get the warning on the DIC that tells me they are open. I cycled the dimmer switch **** multiple times to make sure that wasn't stuck on. I drove it for a while and the lights don't ever shut off. I did pull relay #37 and they all go off at that point.

Any pointers to help diagnose the issue so I don't just have to start replacing parts will be greatly appreciated. I did a search on the thread and the other interior light issues that I found seem just slightly different.

Bill Curlee

Did you by chance turn or bump the DIMMER **** all the way to the clock wise position?? That will turn the interior lights on till battery exhaustion. Press the button till it pops out and see if it is fully clockwise (on the click) if so, turn it CCW (off the click) and see if that solves the issue.

Bill

rooster91

Hi Bill,
Yep, did that. In my post that is what I called the "dimmer switch ****". I actually did it multiple times just in case I thought that I wasn't turning it completely off. :-)

Ok Boomer

Must be the phase of the moon. same thing happened to me this morning; car sat for 2 days - no big deal as it’s my DD but I was in for a bit and using my wife’s car.
went out this morning , started car- no issues - and after 5 minutes I noticed map light was on. Hit the switch on left side of mirror - still on so I ttried right side - still on. Did this several times and still on. Ran my errrands, still on after 60 minutes. To rectify I just pulled fuse for courtesy lights from box on passenger side under carpet. Will plug in fuse tomorrow to see if lights are still on.
If so, will disconnect battery and reindex windows, etc.
Thought I try fuse first.
any ideas?

rooster91

So, I'm still chasing this problem and getting frustrated so I only work on it now sporadically.

It seems to be concentrated to Cell 114 (Courtesy Lamp Relay Control) of the lighting systems. It runs off of microrely 42. I have purchased a new relay and still have the same issue.


I also found this wording on how the system works:

The courtesy lamps are used with the courtesy lamp feature. The BCM activates CTSY LP micro relay #42 by grounding CKT 690. Battery voltage is then supplied from the CTSY LP micro relay #42 through CKT 740 to the courtesy lamps.

To me it now seems that the BCM is always grounding out CKT 690 and that is why the lights are staying on. Does anyone know how to check this before I start looking for a BCM? Looks like I'd have to drop at least a couple hundred bucks for one and would like to be sure before I buy.

mmartinez

One possible cause besides the BCM could be the switch/sensor on one of the doors has failed maybe? Older cars used to have a switch that got depressed when the door was closed, but newer cars have it built into the door latch assembly.

rooster91

Thanks, I thought of that but I assumed that I would get the "door ajar" message on my DIC. I'll see if I can find that circuit.

mmartinez

Sorry, I missed that on your first post, have you tried a power reset, disconnecting negative power cable for 5 minutes or so, it is something that always seems to work on my car.

ALLEN007

This is what happened to my wife's 2012 Ford Edge. Switch failed and thought the door was open all the time, so lights stayed on all the time until the battery died.

rrwirsi

Today I went out and found my battery dead. I remember when I was cleaning the interior 2 days ago I found the interior dimmer **** just on after the CW click, So I clicked it off by turning it CCW. Now a dead battery. Reviewing the C5 manual I found this, "Be sure not to have this **** turned all the way down with the lamps on during the day. Your Driver Information Center (DIC) may not be visible.". Seems to me the instructions are saying to have the switch turned on (CW after the click) but not completely off. Thoughts.

DWAVette

I recall the headlight switch worked that way with my 1970 Ford pickup. Twist until it clicked then the interior lights came on.

I can see how a GM technical writer would be correct in describing the operation that way. Turn the switch “down” blah blah blah. When the clicking notch is passed over, it now becomes fully energized and “up” all the way. It just so happens that “up all the way” is going the same direction as “down all the way”.

It certainly could have been described more clearly, but I see the point.