This wire runs from the red fusible box on the passenger side and goes under the pcm into the firewall. I've tried searching for what it could be and I'm coming up with nothing. Red/black wire with yellow fuse like connector in the middle of it. Figured it might be something custom or something for an alarm that was once on the vehicle, im unsure.

Ill come back to edit the post once I can get pics on here.

 

Looks like someone added it, since it's not inside the wire loom, and GM doesn't use the crimp connector shown. Go under the passenger side of the dash and see where it goes.

 

Not factory.

 

It looks like the wiring setup for an Auto Trix (or homemade) power window fix kit. Other posters are correct to follow the wires inside. They'll come out behind the footweel kick panel. Check in your p/s door panel under the switch panel and see if you've got 2 relays in there. Its a common fix for window motor undervoltage. If you've got manual windows....
HTH

Tim.
ps. You may want to add a signature w/the details & specs for your car.

 

The AutoTrix window setup was the first thing that crossed my mind, but wasn't sure of the actual wiring. I'll try and trace it to figure it out. I do have a sig. not much to put in though

 

Sorry I missed your sig! Its not visible in the reply screens. Good luck.
Tim

 

I figured out what it was, it does appear to be the AutoTrix window kit. But here is no fuse and I can't find the info on what type of relays or fuses it would need. I only know it comes with 2 relays and 2 fuses yet only needs one fuse. Anyone know what fuses and relays I need?

**edit**

It uses a mini fuse and the relays are standard. Anyone have an idea of what amp fuse would be good?