2012 GMC Sierra Electrical Issue. Need Help!

jkking72 · October 29, 2020

I am having a serious mechanical/electrical problem and I really am at a loss of where to go. I pretty much tore my truck apart to put new carpet and utility lighting throughout. In doing so, I was trying to go through the main grommet in the firewall with an exacto and it must have hit something. I pulled back and the tip of the exacto was black and bent. Unfortunately, I had the positive of the battery disconnected and not the negative. So I am thinking that I grounded something out. Now, the horn, ac/heater blower, and an airbag notification is on. I checked all the fuses I could find. It looks like they are all intact. I really need some guidance as to what I should do next. Should I replace all of the relays and fuses anyway? Reset the computer? I am truly at a loss and I'm really pissed at myself for putting myself in this position. Let me know what your thoughts are and THANK YOU SO MUCH IN ADVANCE!!!

Edited October 29, 2020 by jkking72

04z71crew · October 29, 2020

Sorry you are having a tough time. Electrical problems can be a not so fun to track down. Do not just go replacing random relays and fuses etc, waste of time. You really need to figure out exactly what wiring harness you cut into. If its only a few wires you can take the wire loom off and solder in new connections with new wires. Heat shrink it all afterwards. If you cut half of them you are better off scrapping that portion of the harness and replacing. So I would find the harness, assess the damage, and look up a schematic for the wiring harness. You could have blown a fusable link that is burried in the harness itself as well. But first you need to know exactly what kind of damage the harness has.

I wish you good luck and next time just use a good quality hook pick to pull the grommets. Channelock makes a real nice made in the USA set for like $10 it has served me well. I have kicked myself for things in the past it happens to all of us. Don’t beat yourself up every problem has a solution you just need to know exactly where is located. You can do it.

jkking72 · October 29, 2020

I really appreciate you taking the time to get back to me and also write the encouraging words. I have been very upset since finding all of these problems out. The area that I was trying to go through was the main wiring harness on the driver's side firewall. All that I had read about it, said to just punch straight through. When I hit something, not only was the exacto blade, but a puff of smoke came up as well. Any thoughts on how to get into the main wiring harness to check things out without too much difficulty?

Thanks again for all of your help!

Jennifer

Edited October 30, 2020 by jkking72

jkking72 · October 30, 2020

I am having a lot of issues getting the "bonnet" off of the main wiring harness. I am thinking about cutting it away to be able to get to the wires and them taping it back up securely. Any help/advice would be appreciated.