Well I can't figure this out and it seems a bit odd to me. I've got a few issues I've noticed with my new to me 99 XJ. First off the AC comp. never engages, and the electric fan never comes on. My mech fan seems to always be running at full speed with the engine on, so I'm guessing that's seized up.

My diagnosis:
Checked relays - swapped starter and fan relay and nothing changed.
Checked fuses for AC Comp and fan.
I unplug the fan while the engine is running and it kicks on.

I have not serviced the AC system on this jeep yet, is it possible it's just bone dry out of freon so the clutch won't engage which causes the electric fan to not work?

Please enlighten me as I haven't gotten too far into AC yet in tech school.

 

AC compressor won't come if the refrigerant level is too low or too high. Time to check with gauges. Mechanical fan should turn when you are sitting still. Should free spin while driving until clutch engages by temp.

 

Low pressure cut out switch is kicking in to protect it when the charge is low. Evaporator leaking is common. If you charge it up, and it runs for a little while, and you smell it in the cabin, that's it. Proper service is to vacuum it down, see if it holds vacuum for a specified time to verify no leaks, then add refrigerant and the PROPER amount of oil. Many will say also advisable to change the accumulator dryer and expansion valve at that time as well. Or just bring it to a competent service place, either way going to cost a little bit.

 

I work at a dealership. I evacuated and recharged the AC to find out the compressor is seized. As for paying for it to be done, I don't think so lol. I'm in my last two weeks of tech school so I'm able to repair it myself. Thanks for the input everyone

 

AC is a pain to work on, but DIY as much as possible is really the only economically feasible thing to do on an older car or truck. I know around here with what shops charge for AC work in many cases it would be cheaper to just buy another vehicle that has a working air conditioner.

 

They charge so much because of the equipment needed. AC machines are not cheap, r134a is not cheap(new stuff r1234ya is stupid money right now) and to do a proper evac, vaccuum and re charge(should take around an hour) takes time and in a shop, time is money.

Another thing is for warranty purposes on a new compressor, you have to replace 2 or 3 other peices(accumulator, otube and in some vehicles the accumulator is built into the condessor) and the labor and parts add up quickly. This is why they make bypass pulleys and brackets so there is a cheap option.