Low-side AC reading 80+ PSI???

[bhanson]

Not Fixed. Fuse was blown. :\

I noticed the light wasn't coming on when I pushed the AC button, so once I replaced the fuse that turned back on. The AC started to cool and was blowing cool air, but then started to warm back up again. I measured the PSI on the low-valve and it still reads 80+ PSI.

The air conditioner on my car stopped blowing cool air last Friday on my way home. When I start the car it appears to blow "cooler" air and then slowly degrades into hot air.

I don't know very much about cars, but I figured I could just get away with topping it off with 134a. I have a pressure gauge and I understand the procedure, but when I insert my gauge on the low side the reading it too high for my meter.

Adjusting for temperature (it's about 98 degrees right now) it should read optimally about 50-55 PSI and lower if it needs to be topped off. My gauge only goes to 80 PSI and when I plug it in it pegs the meter.

Is there an explanation for why the low-side gauge is showing so much pressure?

 

[LTC8K6]

Well, you have to learn why the fuse blew.

 

[SuperSix]

If the compressor isn't running, the high and low sides will equalize - so 80 isn't surprising.

WHAT fuse blew?

 

[bhanson]

If the compressor isn't running, the high and low sides will equalize - so 80 isn't surprising.

WHAT fuse blew?

The fuse marked "AC"--it was the first fuse in the box (top left).

The air conditioner seems to be working now. I haven't tried to recheck the pressure--the valve is in an awful spot and it's really easy to burn myself.

Probably unrelated (I think), but my radiator cracked today and I had to get that replaced. Antifreeze was coming out and hitting the hot engine causing white smoke to appear.

 

[SuperSix]

So you replaced the fuse and it's all good.

 

[alkemyst]

http://www.youtube.com/watch?v=PMM80xlon3U

He focuses on Saturns, but his videos are invaluable to all makes and models on A/C

(and other issues).

 

[T2urtle]

If the compressor isn't running, the high and low sides will equalize - so 80 isn't surprising.

that is your answer. with the compressor off it should be somewhat reading ambient temp.

You could have a short in the compressor thats why that fuse popped. Fuses dont pop without there being a reason for it to be.