2nd Gen Non-Engine/Transmission A/C troubleshoot question

[PVanderlugt]

A/C not as cold as it used to be, Compressor cycling 10 times per minute, thought it was low on refrigerant, put gauge on the low pressure side, pressure cycling between 22 and 50 psi between compressor cycles, cycles about every 5 seconds anybody have any suggestions?? A/C has never been my strong side

Thanks in advance

Pete

 

[jhoughton]

While the compressor is running the pressure should be between 35-40 psi. When it is not running it may read higher. I believe from what you have described you are still low on freon. If you can check the high pressure it should be between 250-350 for r134. That is where my 99 runs and it still works great even with temps over 100. Hope this helps Jim

 

[PVanderlugt]

Yep, that is exactly what the problem was, added some freon and it is spitting icecubes now, still only running around 30 psi or so, but the can was getting cold, will try to get some more in tommorrow.
Thanks for the help
Pete

 

[JoeBioDiesel]

Hi Pete,
If it's blowing cold, and the compressor is not cycling a lot, I recommend you leave it alone. When it comes to adding refrigerant, the rule "If a little is good, then more must be better" does not apply. Overcharging a system can be a pain in the butt to correct. You always end up removing some oil with the refirgerant.

Joe

Yep, that is exactly what the problem was, added some freon and it is spitting icecubes now, still only running around 30 psi or so, but the can was getting cold, will try to get some more in tommorrow.
Thanks for the help
Pete

 

[PVanderlugt]

Yeah, I will give it some time and see how it does, but for now it looks good and I won't add any more freon.
Thanks for the help
Pete

 

[fest3er]

A/C not as cold as it used to be, Compressor cycling 10 times per minute, thought it was low on refrigerant, put gauge on the low pressure side, pressure cycling between 22 and 50 psi between compressor cycles, cycles about every 5 seconds anybody have any suggestions?? A/C has never been my strong side

Thanks in advance

Pete

FWIW now, your symptoms point exactly to low freon. You turn the system on, and within seconds, the compressor is close to drawing a vacuum (20 PSI). So the low pressure switch opens and shuts off the compressor. Then the pressure returns to a good value (50 PSI) and it turns on again. Low freon. Usually adding one can will, mmm, mask the problem (where did the freon go?).



When it's 90F and humid, I'll put my system on fresh air, fan on high, compressor on, idling at 1200 RPM or so, and add freon until the compressor stops cycling. That will be about as cold as these systems will get under these ambient conditions. I then put the system on recirculate, turn the fan down, and drop the idle; the compressor usually starts cycling again, because demand for cooling is now minimal.



The local A/C pro in Roanoke told me these systems just don't work in high temps and high humidity. He's wrong. They do work reasonably well if enough freon is put in to allow the system to work properly. Around town I might have to put it on recirculate to get almost adequate cooling. But on the highway when enough heat is being pulled from the condensor, I can usually run fresh air and have to turn the temp up a little to keep from turning myself into an ice cube. But at 100F and high humidity, the system *is* somewhat marginal.



N

 

[PVanderlugt]

Fest3er,thanks for the info, makes perfect sense now. Where did the Freon go??, Don't know. Truck is 5 years old now, and A/c has never been serviced.
Started to noticed last year that A/c was not so cold anymore, but still not bad.
Have serviced system with about 1/2 a can and will see how it holds. System running at about 30 psi now. If leak gets any worse, will do some more investigating. Thanks foreveryone's time
Pete

 

[DLBurns]

I have the same problem... added a can of freon and the temp still doesn't get real cold. I was up in Sacramento this weekend and it was hot... ran the AC coming back from Turkey Creek and it was marginally cool after about 40 minutes of driving time. . what is the best way to check for leaks?

Dave