CantDrive55

1999 Jeep Cherokee 4.0L AW4 199K miles

I have recently installed a new A/C compressor due to the 100 degree weather we've been having, and now I can't use it. Every time I have my headlights on, A/C on max, the engine wants to start to stall but catches itself. However, as soon as I step on the gas a little bit, it stalls completely. It will restart everytime, but it feels like a very weak idle. RPMs are 800-900ish at idle so I know it's not a weak idle but for some reason it feels like it.

I tested the battery and alternator. The battery was 5 years old, so naturally that's the first thing I replaced as it needed to be replaced anyway. That didn't help it. Engine off, 12.6V. Engine idling, no accessories on, 14.5V, headlights and A/C on max blast, 12.8V. This makes me believe that the alternator tested good so that was ruled out.

I did look for any grounds/shorts and I did come across this dark green/red wire located in a wire loom on the passenger side near the headlights. According to the Haynes manual, I could be wrong, but it either leads to the fuel injectors, ignition coil, or alternator. It does look like it travels with a loom that goes under the radiator across the header panel. It looks as if it was cut. However, I have no idea if that wire has any significance and I have been unable to locate any other missing wire of the same color code.

I know that I will have to take out the header panel to trace that wire but I was hoping to see if anybody could verify what exactly the dark green/red wire belongs too or what it could belong too, and if that could cause the problem I am having.

Or should I hunt down anything else that could be the issue? Thank you guys!

CantDrive55

Update on the wire. Just the wire simply going to the horn is all. Took the header panel off and traced it and the horn was the culprit. However, as for the stalling problem, I compared it to my other XJ which runs perfect. I did have a missing ground cable from the negative terminal to the fender. I added that and it did help some but it could still run better. My guess is I need to refresh and over look all the connections. Any specific ones to look for? Sensors I could check, clean? A link would be great can't seem to find one. Thanks in advanced.

EDIT: I did a bit searching and some people suggest cleaning the IAC?