02 A/C Compressor Not Engaging

[BaxterJeep]

AC didn't work when I bought the vehicle a few months ago. My mechanic installed an AC system repair kit that included a new drier and gaskets, etc... changing this stuff out means that there is no refrigerant in the system right now.

I brought it to a guy I know who does AC charging and he put gages on the system and tested for leaks and there were no leaks. He told me to start it up and turn the AC on, and when I did he said the compressor is not engaging. He checked a bunch of electrical stuff, got underneath and did something with the compressor and then told me that the compressor was bad and needed replacing.

I got home and looked online and I see where there could be several other things that could be the problem other than the compressor being bad. Relays, switches, and wiring. Also, I read a post where it was said that as you fill the system with refrigerant, the low pressure switch is activated and the compressor will start up.

I don't want to just replace the compressor without checking a few things and without a little feedback from you'all.

Thanks,
Greg

 

[Irun]

Not entirely clear from your post. Is the system charged, and was oil added, or already in the compressor?

 

[BaxterJeep]

The system is currently empty. Some oil was put in the dryer when it was installed. I saw my AC guy pour some oil into the tube that he was connecting to the 134a tank, but I don't know if any of that ended up in the system because he never charged the system because the compressor was not engaging.

Greg

 

[ColoJeep]

The system is currently empty. Some oil was put in the dryer when it was installed. I saw my AC guy pour some oil into the tube that he was connecting to the 134a tank, but I don't know if any of that ended up in the system because he never charged the system because the compressor was not engaging.

Greg

If the system is empty , the compressor won't turn on . It's operating as designed. Your A/C guy isn't .

 

[BaxterJeep]

If the system is empty , the compressor won't turn on . It's operating as designed. Your A/C guy isn't .

LOL. Thanks, I'll talk to him about this.

Greg

 

[BaxterJeep]

Ok, I just talked to my AC guy. My mistake, he filled the system with 134a. He traced power all the way to the compressor, so he is sure that I need a new compressor.

Greg

 

[PG.]

I assume the pressure high and low side looked good to him and all electrical is good than you got a bad new part which happens. Only other thought was a restriction but that would lead to low side pressure problem if i remember right which would show on his gauge.

 

[hear]

I've only briefly ever looked at this system, but I thought the FSM says to jumper the pressure switches to see if the compressor will turn on, in order to rule out a bad switch/wiring. Either way, there is a troubleshooting guide in the FSM that's worth going through before you spend more money.

 

[CharlesHS]

Lets ASSUME (yeah I know) that both the LPCO and HPCO are working properly and there is power all the way to the compressor clutch; I still haven't read about testing the clutch to see IF it's engaging OR IF it is not engaging whether or not clutch itself is bad or out of adjustment.
The fact that your mechanic states the compressor needs to be replaced (not operating) could confirm there is a problem with the compressor clutch and he feels replacing it is easier than dealing with repairing the clutch mechanism.
Either way he should have tested the LPCO, HPCO and clutch engaging prior to filling the system with refrigerant. Now you could pay for evacuating the system, placing the system under a vacuum and charging the system twice.
Will the mechanic credit you for the refrigerant used previously and other steps performed without testing all the system components first (his fault) ?

 

[BaxterJeep]

As far as I know, it's the original compressor. I haven't replaced that yet.

He did jump the switches while he was checking over the electrical. I'm sure he's checked everything over, it's just that I don't know enough about it to explain what he did, and I made the mistake of assuming there was no refrigerant in the system because I didn't see him put it in. I saw him hook the tank up and open the valve, but it happened so quickly.

He said he would refill the system after I replace the compressor. I'm sure he'll be fair with me about the cost, as he always is.

This is a salvage yard/repair shop/body shop and the owner, Lee, and all the guys that work there are very nice people. I feel very comfortable there. It's a laid back vibe. One of the guys that works there, Dan, is the mechanic who comes to my house after hours to work on my vehicles. Dan installed the AC repair kit, but didn't check the compressor, which he should have done before sending me to Lee to have the system charged. I think Lee assumed that Dan had the system ready to go, which is why he didn't check the compressor before filling the system.

This illustrates the type of thing that happens when you have multiple mechanics doing work on a vehicle and when you're trying to save money on maintenance by hiring a mechanic to work after hours. If I had brought the Jeep in to a shop for the work to be done, it would have cost me a lot more money than it will the way I'm doing it. But doing it this way does cause other problems as you can see.

Greg

 

[hear]

This is why most of us here do our own work, or at least advocate for a significant amount of troubleshooting before we start spending real money. Its easy to end up spending money twice if you didn't actually find the root cause first.