Automotive Air Conditioning Information Forum (Archives)

Grbullets on Fri August 27, 2010 3:45 AM

Year: 2006
Make: Chrysler
Model: Pacifica
Engine Size: 3.5L
Refrigerant Type: 134a
Country of Origin: United States

My A/C has been working great this summer until now. With A/C on, my air slowly started getting warmer and warmer over the course of about 3 weeks. When it stopped blowing cool air I noticed the A/C clutch only operating for 2 seconds and it would stay off for 10 seconds or more (A/C on)and it would keep cycling like this. Sometimes it would stay on for 30 seconds or more but not very often. When it did stay on for 30 seconds the air from the vents would get cold. I checked the charge just before it got bad and it was fine. Gauge shows fully charged. Eventually, it stopped cycling at all. Up to this point, there was no noise at all from the compressor. Then the clutch started making a light noise (A/C off) like it was rubbing lightly on the plate that got worse and worse over about a week. I noticed thick black stuff splattered around the clutch area which turns out to be the rubber damping material on the front of the clutch. After a few more day's, a metal ring that is part of the damper came loose and is flopping around freely making a ton of noise when I start the car. I assume that this is a freak of a problem that could only happen to me. What I need to know is why did this happen and can the clutch be replaced without having to replace the compressor? If so, should the coil be replaced with a new one or will it be OK to use the existing one if it checks out with an ohm meter? The vehicle is an 06 Chrysler Pacifica with 3.5L engine, 60K miles. The compressor is a Denso 10S20. I'd prefer not to open the system if at all possible. Any help is greatly appreciated. Thanks!....Dave

ACProf on Fri August 27, 2010 7:22 AM

"Gauge shows fully charged."

Not possible. No gauge can show the AMOUNT of refrigerant in the system. Gauges only show the PRESSURE exerted by the refrigerant in the system, which is the SAME whether there is 2 oz or 2 pounds of refrigerant present. I'm sorry to say that you fell for the sales hype (not really your fault, but don't believe everything you read on a can of fix-it-all") and the label of the toy gauge on that AC kit. There should be a law against those kits!! If you measure the pressure of a full can of R-134 and then use half of it, and measure the pressure in the can again, the pressure will still be the same until the can is completely empty.

THe symptoms you describe sounds like your system is nearly empty of refrigerant and so the compressor is now lacking lubrication flow as well. Its getting harder for the clutch to turn the compressor and thats what's burning up the clutch. THe clutch is cycling because the computer system knows the system is not working and shuts down the compressor. THe front seal on the compressor shaft is likely toast now too.

Chances are the compressor is limping along on its last leg now and replacing the clutch will be a moot point when the compressor innards lock up. The clutch burning up was a RESULT - not a CAUSE of the problem. Kind of like replacing a blown fuse does not fix the electrical problem that caused it to blow.

Unless you have (or are willing to buy) the necessary tools, go to a REAL AC shop, (not Joe's Tire, Radiator, and AC shop) and have the refrigerant recovered (and measured). THen have the entire system flushed, compressor and accumulator/drier replaced, and then recharged to specifications. While there, have them check for any remining leaks too.


Oh, and throw away that toy gauge and that AC "death-kit". You can borrow some REAL gauges from the parts outlet and then correctly measure the low and (especially) high side pressures and report those reading here to get a free diagnosis if you wish..

Hope this advice helps you in your repair decisions.

iceman2555 on Fri August 27, 2010 11:04 AM

Just a thought....considering the possible failure of this unit....and the amount of debris cast into the condenser inlet as the result of this failure.....strong suggest to replace the condenser as part of this repair procedure. Conducted evaluations on three similar failures this week.....new compressor installs...flush....possible compressor issue in one and the other two were performance issues....all issues were rectified with condenser replacements. Just my $.02 worth.
Good luck

-------------------------
The strongest reason for the people to retain the right to keep and bear arms is, as a last resort, to protect themselves against tyranny in government.
Thomas Jefferson