I have a 2006 Legacy 2.5i and the other day it was really hot and humid (90+ degrees). I got in my car in the middle of the day and turned on the AC and it never got cool. It had been not cooling so well at idle, but when I accelerate it would cool back down. This was the first time it just didn't work at all. I could hear the compressor trying to kick in and then kick back out.
I just thought it was low on refrigerant, so I went to Walmart and bought the can with the gauge and was going to top it off myself. Well, when I put the gauge on with the compressor running with AC on high, it's showing between 40-45 on the gauge which is labeled "Alert." Is this thing overcharged and the high pressure switch is kicking it out? Remembering from my physics class gas expands when it's heated, so it makes sense the pressure would go higher on the hottest day so far this year.
When I got off work the same day and drove home, it worked like normal. It was only when it was outrageously hot outside and inside the car at lunchtime.
Is it as simple as being overcharged or is there something else that could be wrong?
The outside temp when I checked the pressure was around 80 and the AC was cooling properly at that time.
Edited by huffman142, 18 June 2014 - 06:08 PM.