Hey Guys - Figured out why my car over heated the other day. The a/c high pressure switch is not activating the aux fan. I think this is because a/c pressure is not high enough, if I jump it, fan turns on. my a/c is blowing cold air, but pressure gauges show it is not changing. I'm seeing 80 PSI on the LOW side and 75 PSI on the HIGH side. And it is not changing, the compressor just stays on.

It is 75 degrees out and 50% humidity right now. Its r134a conversion.

Any ideas what it may be? Am I low on r134a ? Low side seems to high for that???

 

No way the AC is REALLY blowing cold air if the pressures are what you say.

They should be around 250 - 275 and 35 - 40.

Sounds to me like a gauge issue of some sort, or wishful thinking about the air temp. Those 2 facts are fundamentally incompatible at a basic physical level, and then some. It is a Not In My Universe kind of problem.

 

Well sheet, I tried to double check the gauge. the dials are moving when I open them to check pressure. Will do again tomorrow. Beth is calling. Its a good gauge, yellow jacket, didn't want to cheap out on high pressure equipment. Kind of like my eyes and limbs. but the air is cold. didn't have a single beer during this test.....