For some reason, and not always, my AC will just stop working. The vehicle has rear air. For example, when going on vacation and ten minutes into it, my step daughter told me to kick on the rear A/C via switch above console near rear view mirror. Fairly soon, the A/C started blowing warm air all together. So I switched it off. 45 min later I kick it back on, front only and it worked great. It is acting up more now though, where(just using the front mind you) it won't kick on at all. Then other times it works fine. The pressure is fine and it blows ice cold when working, but I am kinda stumped. It is only truck I got but hate to dump a bunch of money into via labor. Any advice would be great. Thanks.

 

What year ?

Need to make sure the fans are running when the AC is on (the fans in the engine compartment)
When the AC has been running verify the cold line is cold and not warm near the compressor, the hot side should be hot but be careful as it can be very hot...
Check the accumulator, it too should also be fairly cool...
Its possible you have a bad pressure switch at the accumulator causing the compressor to short cycle...
When you say the pressure is good, is that because you had it checked or you checked it yourself with a proper set of gauges?
Did you see any bounce/unsteadiness in the gauge needles? (a good sign that the compressor is getting old/failing)

 

2001. Had pressures checked by mechanic. It seems to kick compressor on sporadically. Like I said, first time it did it was when I flipped on rear A/C. Now it just does it regardless. Lines are like u said should be doing. Another mechanic said it was a blend door or main controller on dash.

Need to make sure the fans are running when the AC is on (the fans in the engine compartment)
When the AC has been running verify the cold line is cold and not warm near the compressor, the hot side should be hot but be careful as it can be very hot...
Check the accumulator, it too should also be fairly cool...
Its possible you have a bad pressure switch at the accumulator causing the compressor to short cycle...
When you say the pressure is good, is that because you had it checked or you checked it yourself with a proper set of gauges?
Did you see any bounce/unsteadiness in the gauge needles? (a good sign that the compressor is getting old/failing)[/QUOTE]

 

next time it goes warm; rev the engine up to 2500 rpm and hold it there. if the a/c starts getting cold again your compressor is tired.

 

It will get warm if I'm driving down the highway sometimes. I can switch it off and comes on again. Sometimes works just fine. The rpm at 2500 has no bearing for this problem. Like a gremlin in the system.

 

Meaning if I switch it off then back on later, will work fine. Not always the case though.

 

then your compressor is probably fine. 14 yo compressors are a common cause. another way to check the compressor is to obtain readings with a manifold gauge set.


Is your refrigerant level correct?


their is a tsb for this concern for an updated low pressure switch located at the accumulator. Maybe do a search for it.