1991 XJ Laredo, RWD, 199,000 miles
I have recently realized that a small red wire that has been connected to my positive battery terminal as long as I have owned my jeep should not be there. In the meantime, I am leaving it like it is but I would appreciate any help in identifying what this is and where it goes. I tried to trace it but it goes up into the main wiring harness that leaves the PDC.
Background: I have always had starting/idling/electrical issues. I always attributed it to the previous owner allowing the jeep to sit for a few years and jury rigging things together improperly. I also discovered this unplugged connector and im not sure what it goes to either. It appears to have a purple wire and a blue/black wire coming from it. Both are directly behind the battery, near the cruise control vacuum and PDC. First photo is mystery connector. Second photo shows where mystery wire and mystery connector lead to. Third photo is mystery wire that is currently connected to pos terminal.

 

Wiring diagram shows that red wire as "IOD (ignition off draw) Connector (rear of battery)". It goes to the power dist center fuse F2. Not sure on the other connector. I though maybe for rear windshield wiper fluid pump, but the colors don't seem right.

 

Hmm that might be it as I dont have washer fluid pumps. I plan to pull the reservoir from a junkyard later on.

As far as the red one, how would I go about reconnecting it to the PDC? I have tried searching but cant seem to finding anything on this elsewhere.

 

The end in your picture attaches to the battery.