Automotive Air Conditioning Information Forum

Hello, new to the forum. I have a 2011 Jeep Patriot with 65 k miles. About the last 10 minutes of driving home the other day I heard a slight rattle coming from the engine compartment. I stopped and turned off the AC and the noise stopped. Started up and turned on the AC and the noise started again. The next morning it started blowing hot air. I couldn't find a pressure switch, just a transducer. The compressor has one black and one red wire. I wire the red to positive on the battery and black to negative. I heard a slight click but not as loud as usual clutch sound. I started the engine and still just hot air. No signs of leaks anywhere. It was very cold up to the day it stopped working. Is there any other test that could be done, or does it sound like the clutch or compressor is gone? Thanks for any help on this.

By hot air do you mean ambient air? If so, the system could be low on refrigerant due to slight leakage over the years from the compressor shaft seal. Low refrigerant would be the first thing to check because that's the most common problem.

Don't be tempted to try "topping it up." Have the system recovered, ask the mechanic how much refrigerant comes out, compare that amount to specs (chances are it's low), and have the system evacuated and recharged. Your Jeep takes 21 ounces net weight of R-134a, unless the under-hood decal says differently. Then the decal takes precedence.

JohnHere wrote: ↑Mon May 27, 2024 12:41 pm By hot air do you mean ambient air? If so, the system could be low on refrigerant due to slight leakage over the years from the compressor shaft seal. Low refrigerant would be the first thing to check because that's the most common problem.

Don't be tempted to try "topping it up." Have the system recovered, ask the mechanic how much refrigerant comes out, compare that amount to specs (chances are it's low), and have the system evacuated and recharged. Your Jeep takes 21 ounces net weight of R-134a, unless the under-hood decal says differently. Then the decal takes precedence.

Thank you for the reply. Yes the air out of the vents is ambient air.

Proceed with caution, I am concerned that the compressor has grenaded.
As mentioned have a pro shop check it out to prevent more damage. Do not use it in the meantime

tbirdtbird wrote: ↑Mon May 27, 2024 2:37 pm Proceed with caution, I am concerned that the compressor has grenaded.
As mentioned have a pro shop check it out to prevent more damage. Do not use it in the meantime

Thank you for the reply

If memory serves, I don't believe the compressor on your Jeep has a clutch. I think it's a direct-drive, variable-displacement compressor with an electronic control valve. If you jumped the control valve directly to battery voltage, you probably destroyed it. That's why I advise never to jump anything. So at the very least, you'll need to replace the valve and the receiver/dryer.

The slight noise you heard could have been due to a low charge or to a (worst case scenario) disintegrating compressor, as tbirdtbird mentioned. If it's the latter, then you'll need to replace the compressor, condenser, R/D, any lines with mufflers, possibly the TXV, and flush the rest (evaporator and lines/hoses without mufflers).

The compressor has a clutch and a control valve.

14-0667new

JohnHere wrote: ↑Tue May 28, 2024 9:09 am If memory serves, I don't believe the compressor on your Jeep has a clutch. I think it's a direct-drive, variable-displacement compressor with an electronic control valve. If you jumped the control valve directly to battery voltage, you probably destroyed it. That's why I advise never to jump anything. So at the very least, you'll need to replace the valve and the receiver/dryer.

The slight noise you heard could have been due to a low charge or to a (worst case scenario) disintegrating compressor, as tbirdtbird mentioned. If it's the latter, then you'll need to replace the compressor, condenser, R/D, any lines with mufflers, possibly the TXV, and flush the rest (evaporator and lines/hoses without mufflers).

Thank you for that information. What is the best method for eliminating the possibility of a disintegrated compressor?

Tim wrote: ↑Tue May 28, 2024 6:11 pm The compressor has a clutch and a control valve.

14-0667new

Thank you for the reply

Unless you have done AC work before, it might be best to have a shop look at this for you. There is more to it than meets the eye in terms of parts and skills.
Look for a shop that is MACS certified, they are the best. For example don’t go to a brake shop, etc_’