Automotive A/C Axpertise
Posted: Mon Sep 26, 2011 10:00 pm
Greetings:
I seek the Wisdom of the Collective Auto-Axperts for an air condtioning issue with the Wheelman Family Truckster.
Setup: 2004 Subaru Forester 2.5X, 117,000 miles. A/C system never so much as touched. Never needed to. I don't plan to keep this vee-hickle much longer, but need the air to work for the stability of Ms. Wheelperson's Coiffure.
Early Symptoms: In very hot weather, the A/C would disengage briefly, then come on again. Incoming air was Cold as normal when it came back.
Middle Symptoms: I could only get it to re-engage by turning off the A/C button, downshifting, bringing the revs up to 3500 or so, then punching the A/C on again. Air still as Cold as ever.
Lately Symptoms: It'll keep running only if the blower fan is on Highest. Otherwise it cycles off and stays off until I repeat the process above. Air still hand-chilling Cold, so much so that I have to dial up 3 clicks of heat to drive that way.
I read in a Subaru Forum that after 6-7 years, enough seepage occurs to cause the refrigerant to become low even if there's no single "leak". Thinking the system won't turn on with a low charge, I went to Wally World and bought a $23 Recharge kit that features a pressure gauge and an 18-oz. can of R-134A.
The instructions say to charge the Low Side to 45-50 pounds at 86 degrees F. Engine and A/C have to be running of course. I kept filling and filling, but the pressure gauge continued to read between Low and "OK" - like on the line - at 30 pounds.
As I had almost completely emptied the can, the A/C clutch or belt began SCREAMING and would only tip On-Off for a half second - evidently demonstrating that it was OVER-Charged despite the gauge readings.
I let some Ozone-toxic R-134 escape (no Wheelman-Capture System handy...) and went to eat dinner. 100 more Aussies reported Melanomas to their Dermatologists. When I returned, the Air was working, no more screaming, and pressure showing more or less the same as it did before I hooked up the can.
I'd been thinking maybe the compressor was on its last balls anyway, and that I hastened its demise by over charging it and tweaking its bearings. But then how to explain its apparent return to normality? Maybe the hot seals leaked out faster and I happened to check pressure just as it came back to its previous very low charge state? Will it be empty tomorrow?
I've spotted reconditioned comprssors for this car for around $250 shipped online. I figger I'm gonna need one now if I didn't before. Anybody have a better lead?
All Sage and Learned advice welcome.
I seek the Wisdom of the Collective Auto-Axperts for an air condtioning issue with the Wheelman Family Truckster.
Setup: 2004 Subaru Forester 2.5X, 117,000 miles. A/C system never so much as touched. Never needed to. I don't plan to keep this vee-hickle much longer, but need the air to work for the stability of Ms. Wheelperson's Coiffure.
Early Symptoms: In very hot weather, the A/C would disengage briefly, then come on again. Incoming air was Cold as normal when it came back.
Middle Symptoms: I could only get it to re-engage by turning off the A/C button, downshifting, bringing the revs up to 3500 or so, then punching the A/C on again. Air still as Cold as ever.
Lately Symptoms: It'll keep running only if the blower fan is on Highest. Otherwise it cycles off and stays off until I repeat the process above. Air still hand-chilling Cold, so much so that I have to dial up 3 clicks of heat to drive that way.
I read in a Subaru Forum that after 6-7 years, enough seepage occurs to cause the refrigerant to become low even if there's no single "leak". Thinking the system won't turn on with a low charge, I went to Wally World and bought a $23 Recharge kit that features a pressure gauge and an 18-oz. can of R-134A.
The instructions say to charge the Low Side to 45-50 pounds at 86 degrees F. Engine and A/C have to be running of course. I kept filling and filling, but the pressure gauge continued to read between Low and "OK" - like on the line - at 30 pounds.
As I had almost completely emptied the can, the A/C clutch or belt began SCREAMING and would only tip On-Off for a half second - evidently demonstrating that it was OVER-Charged despite the gauge readings.
I let some Ozone-toxic R-134 escape (no Wheelman-Capture System handy...) and went to eat dinner. 100 more Aussies reported Melanomas to their Dermatologists. When I returned, the Air was working, no more screaming, and pressure showing more or less the same as it did before I hooked up the can.
I'd been thinking maybe the compressor was on its last balls anyway, and that I hastened its demise by over charging it and tweaking its bearings. But then how to explain its apparent return to normality? Maybe the hot seals leaked out faster and I happened to check pressure just as it came back to its previous very low charge state? Will it be empty tomorrow?
I've spotted reconditioned comprssors for this car for around $250 shipped online. I figger I'm gonna need one now if I didn't before. Anybody have a better lead?
All Sage and Learned advice welcome.
There should be a sensor on the side opposite the pully where the coolant lines hook into the back of hte compressor motor. This sensor detects when the system is running low on coolant. Even if your system is fully charged or moderately charged etc if this sensor is bad or failing it would automatically shut off the compressor. You can bypass this sensor by unplugging the connector from the sensor and splicing the wires together 
