I have a 99 blazer and recently swapped motors. Under the fuse relay center under the hood there's a wire with a connector just hanging there and wondering if it needs to be grounded or not. Its pretty short and can't see where it would go. I can't remember if it was just hanging there or what. Everything seems to work except problems with the drivers o2. From what I've read the ground to the o2 should be on the back of the head. I think it's just an extra wire maybe for fog lights.

Let me know what you think

Thanks

 

If it is a red wire that looks like it has never been connected to anything ever, it is likely the +12V feed wire to the heavy duty wire connector at the back of the truck. If this is the case, then just leave it where it is unless you have a need for +12V to the trailer harness.

 

swartlkk, Thanks that's the one