small issue on h3.

[Kyle]

okay soo i think its nothing but i thought i would ask to make sure or see if theres a fix. when im driving along or something and i hit the brakes or when im reversing and then press the brake to put the car back into drive i see the headlights dim and then come back to brightness. bad alternator or is it just normal? also when i roll the windows up and they get to the top if i dont release the switches fast enough the cars idle changes lower until i release the switches.

 

[cdarveaux]

Sounds electrical for sure, so maybe bad alternator. And I'm pretty sure that your headlights shouldnt dim...

 

[JGBB04]

Normal, mines done it from day 1. Others have explained it better but basic answer is the alt varies the out put based on demand.

 

[JGBB04]

F5 just covered it here http://www.hummer4x4offroad.com/forum/showthread.php?6332-Jump-Starts&p=110586&viewfull=1#post110586

 

[f5moab]

For further explanation....
In olden days, when this happened, the internal regulator would jump the generator up to full output. Jumping really quick to full output is hard on a generator (similar to an electric motor, most damage occurs when it is first tuned On, not while it runs). So the ECM/PCM will ramp up output to cover the extra load required for the brake lights. This slow ramp up (which is about two seconds) should lengthen the lifespan of the generator (hopefully). So as long as your lights brighten a second or two after the brakes are applied, all is normal.

 

[alrock]

What about when my four 12" subs are thumping to 2000 watts of Pitbull? is the dimming of my lights normal then?

 

[f5moab]

What about when my four 12" subs are thumping to 2000 watts of Pitbull? is the dimming of my lights normal then?

Pulling about 153 amps, I would guess the dimming would be normal. However, you won't care since your brains will be mixed together like a Slurpee.:giggle:

 

[Kyle]

what about when my four 12" subs are thumping to 2000 watts of pitbull? Is the dimming of my lights normal then?

lmao!!!!!

 

[SuperBuickGuy]

My current H3 is my second H3... my first H3 (an 07), went to the dealership several times to "fix" that issue - we all agreed to give up, we narrowed it down to flickering when you hit the brakes at idle.... it won't do it while your driving lights are off. My current H3 (an 08), has the same "issue".. and I think it's simply a load issue - the comment about the computer rather than the rectifier controlling charging voltage does light a potential path to fix (yeah, it's a pun, get over it) it.... if the computer thinks "low load" and it goes to "high load" the lights would flicker once because the computer couldn't react fast enough to prevent a flicker when you hit the brakes.


will someone please hurry up and figure out how to hack the BCM... that issue could be fixed by simply increasing the "normal" voltage level, and the fogs could stay on when the brights are on, and the locker could stay engaged at more than 30 mph, and we could program our navigation/use the dvd play at more than 5 mph...