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Do I need a new Compressor?

When the jeep is cold the AC works fine, once the jeep warms up the AC stills blows but the air is not cool and is very humid. The Freon level is fine, the compressor is calibrated to spec, there is not an icing problem, all switches have been checked. In essence they (used to be a Jeep dealership) have checked everything they can think of to check and the only conclusion they can come up with is to replace the compressor (which stops after it gets warmed up) but freely admit that since they have never had this problem before it might not fix the problem.

Should I have the compressor replaced ($600 estimate)?

Do not throw any dollars at parts until you have a confirmed diagnosis of the problem. A second opinion would be advisable.

You need to take the car to an independent A/C specialist shop.
Check the Yellow Pages to find some in your area.

I suggest you consult an independent automotive AC shop in your area. They are the experts at automotive HVAC.

If the compressor were bad, it wouldn’t work regardless of engine temperature.

I would not replace the compressor based on the information in your post.

The compressor uses an electro-mechanical clutch to engage and dis-engage. The electrical circuit that engages the clutch has built-in safety systems to prevent damage to the compressor and the rest of the A/C system. It is very possible one of these systems has a bad sensor or the electrical system itself has a problem, not the compressor. I agree with the other posters that you need to have the system checked by an automotive A/C specialist before going through the process of replacing the compressor, which is expensive and may not solve your problem…

Every compressor I replaced since 1990 was either leaking or exploded internaly. To say “we can’t think of anything” else as justification is not going to cut it.

What performance figures can you give? like hig.low pressures, cycling rate, outlet temp, realative humidity, lets just see where this system falls on the performance chart.

If you want to just do something, recover charge, evecuate for a couple of hours, charge by weight, report pressures.

Thanks guys, I found a mechanic here on the website, and he recommended by shop and name someone closer to me. I will pick the Jeep up in the morning and take it over to the independent specialist. Hopefully all will work out. I at least feel more confident now.
Thank you again, I will post results.

I had a similar problem on a Ford Aerostar. It turned out to be the fan clutch. Not enough air was being pulled through the condenser. The shop technician was baffled by this, but diagnosed the problem by hooking his gauges to the system. When the system stopped cooling, the pressure went way up. He took the shop fan and directed the flow into the grille. The pressure went down and the system started cooling. Now I don’t know if your Jeep has a mechanical fan clutch or uses electrical fans, but if not enough air is flowing through the condenser, this can cause the problem.

Cools at 42 deg when working. pressure at idle low 32 high 115 – at 1500 rpm low 35 and high 150-120. Clutch cycle switch worked fine (but they would replace with the compressor). They didn’t list a cycle rate not relative humidity ( but the relative humidity I would guess is less than 40% when working and above 85% when not cooling – this would relate to places I have lived - Southern California summers [dry] and North Carolina summers [very wet]). ATC head recalibrated (per service Btn.) with no change in performance. I have an appointment with an independent A/C specialist on Monday.