97 jeep cherokee A/C Problems

[jeepguy4life]

I have a 1997 jeep cherokee with the 4.0 engine. I have been having 2 problems with the A/C. The first problem is that the A/C compressor will not work. I have tried jumping off the pump from the battery to the pump, but no luck. Any suggestions would be great. Note: It has worked sporaticly, and when it does work it is cold.

The second problem that i have been having is that the front 4 dash vents do not blow any air period. The defrost vents work fine as well as the floor vents. I have tried to look under the hood and dash for vacuum leaks, but i have not found any. Also, all fan settings work fine. I have also had the A/C checked (when it works) and it is full of freon.
This is my first jeep and any suggestions would be helpful.
Thanks

[fredjacksonsan]

An intermittent operation like that to me indicates an electrical issue. I would check all connections to/from the compressor, especially the grounds, to make sure they're in good condition. You may have to trace all the way back to the switched in the dash, as they could be the cause.

As far as the vents not blowing where you want them, that can be a vacuum issue; but I'm not the under dash guy, hopefully they'll be along shortly. I can say that there are already some posts about your situation, so if you do a search for vents they'll come up.

[Sidewinder CC]

Originally Posted by jeepguy4life

I have a 1997 jeep cherokee with the 4.0 engine. I have been having 2 problems with the A/C. The first problem is that the A/C compressor will not work. I have tried jumping off the pump from the battery to the pump, but no luck. Any suggestions would be great. Note: It has worked sporaticly, and when it does work it is cold.

The second problem that i have been having is that the front 4 dash vents do not blow any air period. The defrost vents work fine as well as the floor vents. I have tried to look under the hood and dash for vacuum leaks, but i have not found any. Also, all fan settings work fine. I have also had the A/C checked (when it works) and it is full of freon.
This is my first jeep and any suggestions would be helpful.
Thanks

jeepguy4life,

I have a 1999 XJ and am not fully familiar with a '97 XJ; however, I think they are similar.

If you want service instructions for your XJ go to Greatlakes XJ.com. They have factory service manuals and IPC's on line that you can download. http://www.greatlakesxj.com/tech.html

Group 24 of the FSM addresses Heating and Air Conditioning.

Concerning your A/C compressor, I jumper the low pressure cycle switch connector to test the compressor circuit. The FSM addresses this.

Concerning no airflow from your Demister outlets and Panel outlets, you'll find that there is a vacuum operated actuator for the panel/demist door located on the Heater-AC Housing, located under the instrument panel. This actuator may be inoperative. The FSM addresses this also.

Good luck.

[sector95]

Your compressor may not work because the freon level is too low in the system ...this is a safety feature and jumping the compressor to the battery to engage it may not be in your best interests. The compressor is shut down to prevent damage to the system from running with too low a freon level.

The dash vent problem I would suspect is being caused by either a back vacuum motor (used to position the baffle doors insided the amin HVAC plenum) or you have a vacuum line broken/disconnected somewhere that is not obvious.

If it were my Jeep I would bring it to a good shop that does A/C work and have them check out your system. It may be something as simple as topping off the freon (actually R134a).

Hope this helps...

Mike '00XJ

[mastertech1964]

ive run into this situation numerous times on jeeps with some miles on them and ive found that frequently the ac clutch wears and the coil to pull the clutch in gets weak use a test light and verify there is power at the clutch coil wire when the ac is switched on if theres power then you probably have a worn clutch and need to replace it