Automotive Air Conditioning Information Forum (Archives)

mikeal on Mon August 08, 2011 8:33 PM

Year: 2005
Make: Ford
Model: Freestyle
Engine Size: 3.0
Refrigerant Type: R134A
Ambient Temp: 95
Pressure Low: 65
Pressure High: 185
Country of Origin: United States

I'm pretty ignorant when it comes to AC systems, though I am pretty comfortable working on most other things on a car. A year or so ago, my Freestyle started blowing warm on the passenger side then slowly started getting warm on the driver side. I went without until now. I researched the issue a bit and found that these exact symptoms can be fixed by replacing the scroll valve in the compressor, an easy fix.

I stuck a 1/2" nut between the scroll valve and the plate that holds it in, which I read about on another forum as an alternative to replacing the scroll valve, pumped it out for 40 minutes and started to charge it up. After about 12oz, it wouldn't take any more and the pressure was 115 psi on both sides. I jumped the clutch to the battery and it took another 18 or so ounces (estimated). This should put it right about where it should be at 29 ounces. The pressure is at 65/185 and it was blowing cold but not frigid (didn't get a temp.) When I took out my jumper and put everything back together, the clutch won't engage.

A related question: Is there any reason not so jump the compressor by bypassing the compressor clutch relay with a jumper?


Any help with this would be appreciated.

bohica2xo on Mon August 08, 2011 9:37 PM

Well I have never seen a "scroll valve" in a compressor. If you mean the control valve, jamming a nut in it is not a proper repair, and will only cost more later.

I don't recommend jumpering a compressor because it bypasses all of the safety switches. Sounds like you may have a pressure transducer issue.

The freestyle is a picky system, we have seen it before

freestyle blowing warm at idle

B.

-------------------------
"Among the many misdeeds of the British rule in India, history will look upon the act of depriving a whole nation of arms, as the blackest."
~ Mahatma Gandhi, Gandhi, An Autobiography, M. K. Gandhi, page 446.

JJM on Mon August 08, 2011 9:54 PM

I too am confused by "scroll valve" in the compressor.

The compressor in this vehicle is a scroll type, but I don't how the compressor can be serviced without specialized tools. I also don't see how shoving a nut in the compressor will be of any help. It wasn't there from the factory.

I also don't see any mention of pulling a vacuum or oil replenishment.

The reason the A/C was blowing warm on the passenger side then drivers side was likely because the system had a leak, which should've been repaired. Peanut fittings are the biggest culprit, even if a step up from springlocks. If the compressor wasn't pumping enough and the system were properly charged, both sides would have the same temperature albeit insufficent. But now the compressor definitely isn't pumping enough based on those pressure readings.

The TXV inlet screen should have also been checked for debris, given how low the charge went.

Joe

When considering your next auto A/C purchase, please consider the site that supports you: www.ACKits.com

mikeal on Mon August 08, 2011 10:29 PM

Thanks for the info. I'll test the transducer and order a replacement scroll valve. In the thread you linked, you said that the pressure PID can be checked with a 'shop level scan tool.' Is that something that I can borrow from an auto parts store? If not, what is the cheapest reliable unit that I can get?

Thanks

mikeal on Tue August 09, 2011 10:03 AM

mikeal on Tue August 09, 2011 10:34 AM

Quote
Originally posted by: JJM
I too am confused by "scroll valve" in the compressor.



The compressor in this vehicle is a scroll type, but I don't how the compressor can be serviced without specialized tools. I also don't see how shoving a nut in the compressor will be of any help. It wasn't there from the factory.



I also don't see any mention of pulling a vacuum or oil replenishment.



The reason the A/C was blowing warm on the passenger side then drivers side was likely because the system had a leak, which should've been repaired. Peanut fittings are the biggest culprit, even if a step up from springlocks. If the compressor wasn't pumping enough and the system were properly charged, both sides would have the same temperature albeit insufficent. But now the compressor definitely isn't pumping enough based on those pressure readings.



The TXV inlet screen should have also been checked for debris, given how low the charge went.



Joe


The scroll valve that I mentioned is the control valve, as bohica said. It is easily accessable via a panel on the compressor and the only tool needed was a 10mm box wrench. You are correct, the nut was not there from the factory. From what I read, adding the nut bypasses the valve, effectively making the compressor non-variable. It is a fix that has worked for several people on another forum with symptoms similar to mine.

I did not pull the compressor, so I only added 1 oz of oil. I vacumed the system for 40 minutes before addding freon.