I'm looking around under the hood tonight wondering why my truck sucks and I found this connector unplugged. I don't have a clue what it is or why it was unplugged. It looks like it connects two harnesses together. One end goes into the loom that goes toward the back of the truck down the frame rail. Anyway, I plugged it back in and the truck still has issues, but what I'm wondering is what was not working while this was unplugged? No telling how long its been like that either. I don't ever remember unplugging it and it snaps together tight. The plug is located between the fuse box and the firewall down by where the harness goes into the fuse box. Here are some pics. Can anyone tell me what these wires are for?