Headlights will not turn off!

[rlrnr53]

Got out of the truck yesterday morning, and the headlights woild not go off. Finally got them off by setting the park brake. Same thing today, used the park brake to turn them off, but when I tried to go for lunch, the truck wouldn't start. Charged the battery and run for about 20 minutes. Left work this evening, and truck started every time. After getting home, lights were off. When I went out about an hour later to get something out of the truck, the lights were on again, and the only way to get them off short of pulling the relay or removing the battery terminal, is to set the park brake. I'm thinking that the BCM may have have taken leave of its senses. Has anyone had anything similar happen to them? I'mhoping that a BCM switch may do the trick since I have three of them siting around. Maybe I'll get time in the next couple of days to look at this problem.

[HenryJ]

Some stuff to play with:
AHL - Press the dome light switch four times. Does it chime and turn to manual operation?
Is the multifunction switch stuck back in flash to pass mode?
Stuck relay?

[rlrnr53]

Will try to check in the morning, But I removed the headlight relay this afternoon and could feel it clicking as it was inserted.

[F9K9]

........Is the multifunction switch stuck back in flash to pass mode..........

I'd look hard at the switch itself. It's not a "dealer" only part.

[rlrnr53]

HJ, everything you suggested checked out, but in googling the problem I found a thread on the same problem on a 2000 or2001 yukon. The thread suggested checking the headlight switch of continuity between the white and black wires with the switch in the on position. After checking the switch I found no continuity beween the two. Everything else I have checked has been OK. I should know something Friday afternoon weather permitting. Ths switch should be in at NAPA then. OE switch $165.00+ including my discount, Napa about $45.00. Reed, looks like your suggestion may be right, but could you come retrive your water fowl, I don't neet any more bad luck, or visits from MR. Murphy. Thanks for the replies.

[F9K9]

.....................Reed, looks like your suggestion may be right, but could you come retrive your water fowl, I don't need any more bad luck, or visits from MR. Murphy..............................

I hope you didn't jinx yourself by saying that the switch may be the problem and I was correct. A lot of part store's electrical replacement parts get a bad rap for good reasons. Non OEM O2 sensors and our fuel pumps deserve the reputation that they have.

I was thinking about a recent situation, that I had with my Rubicon, when I suggested the MFS. Coworkers at work would tell me that I left my fog lamps on. They were turning themselves on and I had to pull the relay to cure it. Searched here and there for a replacement and had already decided to eliminate the fogs altogether. Found a post on a forum that lead me to Auto Zone. Looked online and found a replacement switch for $50 and change. Ordered it and it arrived in a "Duralast" or something box. It was the same OEM unit right down to the "Mopar" molded into it. Cheapest OEM part I had located previously was $100+. I really hope it works as a "fix" for you!

[rlrnr53]

We've been using some of NAPA's electrical products for the last couple of years with good results. We've had good luck with most of Auto Zone's stuff, not real happy with their brake parts. We have a new parts store that has started a few months ago, but haven't had a chance to try them since they're about 25 minutes away on a good day, sometimes twice that at certain times of the day.

[rlrnr53]

Picked up the new headlight switch this afternoon, after install, everything is back to normal. Reed, you can have your Mallards back for now, and I hope Mr murphy has left to visit someone else. Thanks to those that offered suggestions.

[F9K9]

Screw the Mallards. I have gotten a little tougher thanks to the forum, Brule and just plain old age. I'm not unlike LT. Dan from the scene in Forest Gump where he is shaking his fist in the storm scene, where is is strapped to the mast. Is that the best you can do?

[ApproachMedium]

Humm. I wonder if this could be the reason why my low beam headlights would randomly NOT work? Could a headlight switch cause the same kind of reverse effect? Id be damned if thats the problem since it seems that switch has had issues with staying lighted ever since I first took the dash apart lol.

So far I know its a ground not going to the relay, thats as far as we have traced it back. I put a temp ground wire in at the pass side low beam lamp and the lights work now, however anytime the high beam bulbs are active, now the low beam bulbs are as well. So yes, when my DRLs are on theres lotsa light.

[rlrnr53]

I found the answer for my problem by using Google. For your Problem, I'd try getting a wiring diagram from a factory service manual. Then too, you may have problems with the BCM. That's one black box that GM 's designers would have been better leaving out.