I have a 1999 Cherokee 4wheel drive, 5 speed manual and a 4.0L straight 6 and my air is not blowing cold air at all. I hear the compressor cycling on and off, but the air never gets cooler than the outside air. I had the refrigerant checked and it is fine. I also replaced the relay for the cooling fan and that worked the first time, but now the relay is good and the air is not cold.
While looking under the hood this morning I found this connection and I do not know what it goes too. Anyone have any idea?

 

I am pretty sure that would be the connection for the under hood light.

 

you hear it look under hood is it going on and off is the low pressure line gettomg cold the fat line is low skinny is high

 

ok, thanks...there is no underhood light...that would explain why nothing is hooked up to it...

 

ok, it cycles on and off every 5-6 seconds. I see it engage. the high pressure line is hot, the low pressure one is ambient temp.

 

Usually that quick cycling is a sign of low refrigerant.

 

Ok, thanks. Headed to walmart to get some.

 

Ok guys, thanks. I bought some 134 and charged it up. it got cold...yay. I had my parent's neighbor check it out with his stuff a year ago in his garage, but he said it didn't need charged...it was free so i guess you get what you pay for. I probably have a small leak so will buy some with a dye in it so i can find it...thanks again.