HI. New to the site here. Stumbled upon it googleing for a solution to me blazer promblems.

My security light was on solid, no interior lights and wound not start. After searching this form all signs pointed to the ignition switch. I also notice that the tbc fuse under the hood was blown, so i replaced it. As soon as i put a new one in it blew. Next step was to disconect the ignition switch an replace the fuse again. It still blew. That ruled out the ingition switch for me so I reconected it. Next i disconected the 3 wire packs at the body control modual replaced the fuse and it did not blow. pluged the 3 wire packs back in and everything was fine. This just don't make sense to me. Is this an idication that the bcm is groounding intermitanly? Anyone else have this problem before. I just don't want to be stranded again.

Thanks for a great site!!!

 

No one???

 

Sorry that it has taken so long for someone to respond. Electrical problems are one of the most difficult to deal with and often requires some research to give accurate advice. I did not have access to my references last night to respond.

TBC Fuse - 10A - Body Control Module (BCM), Remote Control Door Lock Receiver, and Multifunction Switch (Flash to Pass) - CKT 1140

On connector #1 (brown connector), pin A1 (black wire) is your ground and A2 (orange wire) is your CKT 1140 +12V power supply from the TBC fuse in the underhood fuse block. This circuit is powered at all times as the other side of the TBC fuse goes directly to the battery.

From the sounds of it, I would be looking for damaged wiring at or near the BCM as well as checking for corrosion on connector #1 (brown) to the BCM. Corrosion between the two pins mentioned above could cause a short which might have been partially disrupted when you disconnected the BCM from the wiring harness.

 

Tnanks for you reply. I looked at that last night and found no evidence of a broken wire or corrosion between the 2 mentioned wires. The truck has been running fine since I messed with it. I did discover that the headlight fuse was blown as well. I hate chaseing electrical problems! Is it possible that the bcm it self is grounding out?

 

It is possible that there is an internal problem in the BCM... It is also possible that there is a wiring problem in the harness and moving it temporarily fixed that problem.

 

The harness looks fine. Traced the power wire all the way to the fuse box.
Well thanks for the help. I'll have to wait and see if it happens again.

 

Exterior condition of the harness does not tell you that everything is fine. If something overheated inside the harness and melted some wires together, you may not ever see it on the outside of the harness. Just saying...