I searched the forums, but couldn't find a post about this particular problem. I have had my H3 for about 6 months. A driver told me at an intersection the other day that my brake lights and turn signals weren't working. The cyclops brake light works.

I read in the manual that the "quick" click for the turn signals meant that I had a bad bulb. I changed both of the rear bulbs (not the backup bulbs). The problem didn't go away. I checked the fuses and the fuse for the rear turn signals was blown. I replaced it. The drivers brake and turn lights worked, but the passenger light stayed on all the time--even with the key off. when I started the engine, the fuse blew immediately and I am back to no brake or rear turn signals again.

I am thinking grounding problem, but the light staying on when the ignition is off makes me think it may be a ground short rather than a loose ground.

Has anyone had this problem?

 

Sounds like you are on the right track - and that track will take you to the dealer.

 

The quick blink in your turn signals means one element is burned out, either front or rear and it's just one benefit of having combination brake/turn bulbs. As for your electrical problem, you have more than a ground problem, you have a hot wire grounding somewhere causing an overload which made the fuse blow. The fact that the bulb is staying lit with the key off would be a concern to me and means that you have a hot wire somewhere. Since the brake lights will work with the key off I'd start there and work your wayforward towards the brake light switch. First make sure you have the proper bulbs and that they are installed correctly. Then check the light socket and the wires leading into it, you may have to gain access to the rear of the light housing to check further. If you have added any electrical gadgets lately or accessories where you have to run screws into the sheet metal also suspect those areas. Last but certainly not least, the BCM or Body Control Module, under the passenger side kick plate does not have a real good history of being 100% operative. You may have to make a trip to the dealer to see if it's working properly if OnStar hasn't given you a trouble code. Happy Hunting!

 

Thanks, guys.&nbsp\\; I made an appointment at the dealer for this Friday, but I am going to check everything you mentioned in the meantime.

 

I know you posted this 3 years ago, but my H3 is having an IDENTICAL problem. Do you remember what the remedy was to this problem?

 

Might want to start a new thread. You won't be getting a response from 1trkpny (Last Activity: 06-04-2008 07:25 PM)

 

??

https://www.hummerforums.com/forum/h...signals-18273/

 

Good find.... I searched last night after he posted in this thread and the one he started and I couldn't find anything....

 

Trailer harness is shorted out on the underside near hitch. It has now fried your BMS. $500++ depending on who you have do it.

 

,if this is the problem,
everyone who has NOT had it happenj!!!,the fix; lay down under the rear bumper,feet on pass side,look up and see the cable,push up where it goes over frame,push forward till it "unclicks",,,done.

if u have the short, add insulation to the cable. get damaged stuff fixed.

DO NOT REMOUNT THE CABLE AS IT WAS!! the factory mount created the stress point, just lift it,let it float. if you're nervous nellie,tie it loosly away from the muffler that it will never touch anyway.

this comes up about 4 times a year,should be in "keeper"file

it came up when i got my 10, i immediatly checked and verified the stress problem and when i pushed up it came loose and i realized i had inadvertantly found "the fix" u shud do it NOW,,,or wait till it gets u!!