JMRedwine

So I have this issue with my A/C.

It stops blowing cold randomly. One day, it will be 45 degrees blasting out of those vents. The next day, hot as it is outside.

There's no rhyme or reason to when it does it. Sometimes it's twice a week, then it went a whole month working fine, then suddenly it stopped working, then today it works again.

I took it to the dealer because I hate diagnostics. He put dye in it and found no leaks, so I picked it up and drove it until it blew hot again. He checked, no leaks. He put the sniffer under the dash to test the evaporator. No leaks. When it is working, the pressure reads that it is fine at 50psi. When it stops working it reads no pressure. Then when it starts up its back at 50psi, without me adding anything.

What in the world is happening?

ol"blue

It could be a problem with the AC relay, or a fuse. >->Jeep Cherokee Electrical - 1997 - 2001 XJ Fuse & Relay Identification - Reference guide to the fuses, ratings (Amps), relays and circuit information.
Sometimes the connector becomes loose or dirty.

JMRedwine

My mechanic finally decided this was a the compressor going bad. He said it was showing that it was receiving power but the clutch wasn't kicking on. It was also giving off all kinds of odd pressure readings. He checked all the fuses, relays, the controller, the low pressure switch, and made sure it had the proper weight of refrigerant.

So I had him evacuate the system and I'm gonna attempt this tomorrow. I found lots of good advice by searching. I see most guys do the dryer and the oriface tube as well when they do this job. I get the oriface, as I can see how stuff would get caught in there, but why the dryer?

Jonwebb

What year is your xj? I think i might have an idea depending on the generation

JMRedwine

It's a 1999.

Jonwebb

Ok then i would suggest checking the blend door to see if its broken. The blend door is what mixes the hot and cold air when you turn the temperature ****. A broken blend door can cause the same symptoms your having because it will work but if you hit a bump or turn a corner the door can move to the heat position, cutting off the cold air. Its under the passenger footwell right next to the tranny 'hump' you have to remove the 3 screws holding up the blend door actuator and then just pull down on the actuator to remove it. There will be a plastic rod that sticks down about an inch. Spin that to see what the range of motion is. If it spins freely then its broken