2000 GMC sierra TBC fuse issues

[SuprGoofyGoober]

So the other day i got in the truck and it was dead. Jumped it and good to go. About 3 days later same thing. Once it started I got in the truck and realized none of the lights were working. Headlights, overhead lights, even the dash lights wouldn’t come on. I’ve learned in the past it usually is the TBC fuse. So I pull it. Bam it’s blown. Easy fix… so I thought. I went to put another fuse in and it blows the second it makes contact. Even 30a fuses blow instantly. I know it goes directly to the BCM on my year model and I’ve inspected wires all over my truck and I cannot find a wire that’s grounding out. I dont know if this is a coincidence but I also noticed that my switch button unlock/lock will locks both sides, but when I hit the unlock it only unlocks the passenger side, and the driver side does not make any noise.. so it’s not even attempting… i’ve checked all the driver lock and unlock fuses, and everything is fine. I even swapped them out just to be safe. I even pulled the door off and check the wires to go to the actuator and everything looked good. The real question is is it a chance that was going on with my locks is causing the same issue with the TBC  fuse? 

[Jsdirt]

You'll have to go wire by wire to rule out a short in the wiring. Unless the BCM failed catastrophically, I'd bet on a short to ground somewhere along that run. I'd start by unplugging the connector, and testing for a dead short at the pin - if the BCM is shorted internally, only fix to that is replacement, then programming.

 

If wiring issues were easy to find, everyone would be an auto tech.