Need advice on Cherokee aircon

Hi,

To test the clutch, follow the two wires from the compressor to where they meet and look for in inline connector just beyond. Disconnect at this point and touch the end to your positive battery terminal. You should hear the clutch click. Then start your engine and touch it again to hear the clutch engage and the compressor working.

The R134a is your refrigerant. Lucky you, its the new ozone-safe kind and you won't require a retrofit from R12 should you require a recharge.

Steve

Mike wrote:

Mike did pass the time by typing:

good advice. While AC systems arn't terribly complex, the average backyard mechanic doesn't have the proper service tools.

Yes, see below.

134a is the type of refrigerant used in your system.

Back to the possible problem.

Odds are your low on refrigerant due to a small leak somewhere. Usually in the seals.

Here is how to check the low-side cutoff switch. Do not.. I repeat DO NOT run the AC like this for any period of time beyond doing this check. It can ruin the compressor.

On the Accumulator

is a sensor. Take the electrical connector off. Start the engine and turn the AC on. Take a piece of wire and connect the two pins in that connector. If your low on refrigerant the AC clutch will engage soon as you short these pins.

They make 134a refill kits with pressure gauge. This might be all you need, but pay close attention to the instructions. If your not comfortable with doing this work then you should have a pro do it. Ask them if you can watch, that way if you ever have to do it again you will know what is involved.

R134a is the refrigerant, not the model. If this is the extent of your knowlege, I'd suggest doing without A/C until you either do some serious studying of A/C manuals - or follow the manual advice and find someone who knows what they are doing. Mistakes on this are expensive. As you have expressed a keen interest in you personal body integrity, you should also know that there are serious risks when working on A/C units, especially if you don't know what you are doing.

I checked out the following and it was bang on!. It looks like I am low on fluid after all. This answers my main line of investigation, i.e. is it a simple electrical fault/bad connection etc that could be simply fixed. (I've found over the years that it pays to eliminate the simple things first). I shorted those pins and the clutch came right in. I ran it for about 20 seconds and then shut it all down and it made a stange gurgling sound for nearly as long. The next thing to figure out is why I am low. I have a funny feeling that the vehicle has been apart in a major way some time in its life but I have no history for the car. I can't ask the guy I bought it off as he moved out of the area, address unknown, and I foolishly didnt chck the air when I bought it as it was very cold and I never thought about it. (sounds silly, I know, but I've bought cars in summer too, and never checked the heater!)

I think -grits teeth-that my next step is to an aircon place and just have them charge it up and see what happens. But I might just ask to watch.

Is it a lengthy procedure?

Mike

Mike did pass the time by typing:

That's a normal noise. Your hearing the the system equalize.

Nah. There might be a recall for your accumulator (a Jeep dealer can check to see if it has been done). Other than that, freon loss is usually caused by leaking seals. Totally normal on older vehicles. Even mine needed new seals a couple of years ago.

Hour or less. If they do it properly they will

1) put some leak-check in and locate the leak 2) pump the system down to remove the refrigerant (required by law in most countries) 3) replace the seals or what ever leaked 4) pump the system down to remove any trapped air 5) refill with refrigerant and test

That's about it.

The quick solution is to put in more gas, but again in some areas this is illegal. The mechanic has to fix the leak.

I ditto that advice too. I would like to add that when you take it to the shop to have it serviced, ask them to install some dye into your system. That will help the tech to spot your leak the next time it drops out on you.

Jerry