Need help diagnosing AC issue.

[Austerity]

On friday I was on my way home from work, it was about 100 degrees out. 10 miles into my 13 mile drive the AC started blowing warm air almost instantly as I was driving along at 45MPH. No noises, screeching, nothing like that.

Sunday I purchased from R134a and a gauge assuming I had a leak and figured it was worth a shot.

The compressor is NOT kicking on, and the pressure gauge reads about 110 when the compressor is off, and if I jump the wires at the low pressure switch it drops to about 40 and makes cold air as it should.

The freon levels seem fine, and the compressor and clutch are functioning fine when jumped off.

What should I look for to check/replace?

Thanks in advance.

 

[Leeann]

Sounds like the low pressure switch is bad.

 

[Austerity]

...........Replaced the switch and it works. Doesn't blow as cold (only about 60) but I can deal with that later.

Thanks!

 

[tjkj2002]

...........Replaced the switch and it works. Doesn't blow as cold (only about 60) but I can deal with that later.

Thanks!

If it's about 100 degrees outside and your AC is outputting 60 degrees through the vents your AC system is functioning correctly.When you jumpered the low pressure switch it left the compressor on all the time which did result in lower output temps but will freeze the evap core and then you have no cold air till it thaws.Can blow the compressor also since the high pressure side will be way to high.

 

[Leeann]

Great!

And x2 on what tjkj2002 said.

 

[Austerity]

If it's about 100 degrees outside and your AC is outputting 60 degrees through the vents your AC system is functioning correctly.When you jumpered the low pressure switch it left the compressor on all the time which did result in lower output temps but will freeze the evap core and then you have no cold air till it thaws.Can blow the compressor also since the high pressure side will be way to high.

According to the EVIC it was 83 when it was blowing 60. After driving around for 5 minutes it got down to 55. I think I was just over-analyzing it.

I only bypassed the low pressure switch for a few seconds to see if the compressor was functioning, not more than 30 seconds.