Is anything else wonky? Other electronics? The lights are controlled by bcm. Hopefully it is not fried.

In the harness you repaired the big red wire was constant hot for recharging battery on trailer. The big blue wire was for trailer brakes. Hopefully when shorted it didn't fry something else.

Did you put multimeter in light socket to see if hot or shorted to ground?

 

Everything else seems to be functioning normally. Have not put probes on the socket yet, but if it were the issue, I wouldn't have a tail light. Will have to check it at my shop tomorrow. Is there a way to test a bcm? I grabbed a bcm from another H3 that has identical specs. Can I swap them and determine if my bcm is misfunctioning?

 

Sounds like it may have fried the BCM for that particular circuit.

Can't swap a BCM without a TECH II OBD tool. The VIN needs to be programmed into the BCM along with mileage and other items I believe.

 

TAINTER... Do you know if the bcm on the H3 can be reprogrammed with Tech2?

 

BCM programming can only be done with a TechII. That I know of.

 

Have you checked for a good ground on that socket? I have seen some GM taillight units lose a ground on one socket. I used a jumper wire to the ground on the other socket and it has worked.

 

Probe the socket to make sure you are getting the voltage pulse when it's supposed to be blinking or steady when the brake is on.

 

The socket should be grounded because the backup light works and the tail light works. I did run a multimeter on the contacts within the socket and the voltage was not uniform, but rather fluctuated and when the turn signal was turned on, the voltage didn't "turn on and turn off" as you would expect to create the blinking effect of the turn signal.

 

So... I'm

putting more and more stock in leaning the route of having this new purchase flashed and I'll install it. Seems as though more indicators are pointing back to erratic, inconsistent, or absent signals from the BCM.

 

Sounds like a solid plan since it sounds like you did everything else.