Raynor

I have a 2010 GMC Sierra with major electrical problems. it started out with a dealer telling me it was hit by lightning but I found no evidence of that being so. I replaced the ECM, BCM, and TCM with new modules. Finally got it started and it will drive. my next problem is the dash, radio, hvac, and windows/locks don’t work. Do you think each individual module could be fried or check the BCM again. Plus, whenever I start the truck it acts like the security is going off (lights flashing, horn sounding) but I’m still able to start the truck. Any advice would be appreciated.