Compression Ignition Addict
Join Date: Jul 2009
Location: Marysville, WA
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Air Conditioning Help
About 2 weeks ago when we had our first decently warm day I noticed my truck's AC was not cooling. I finally got around to looking at it this past weekend. The compressor was continually cycling on and off every few seconds.
I have a cheap auto-parts store pressure gauge for the low side of the AC, and I don't know a much about it. I checked the pressure and it seemed low. I added some 134a and got the pressure to read where the charts I have said it should read (about 32 on a 65 degree day) and the compressor then stayed on-- electric fan clutch on and everything. I also added some stuff with red dye in it to see leaks, but couldn't see any. Vent temp about 42 degrees. Now for the past couple days I have driven it in the mornings and it cools nice, but by the afternoon with warmer temps, it's not cooling nearly as much.
Today on my drive home I couldn't get the vent temp below 60 -- way too hot. When I got home, I opened the hood and the compressor is cycling every few seconds again. I checked the pressure, and the pressure is higher than it was before, but looks like it's within the chart specs for the temp today.
I jumped the low pressure switch and it acted the same way.
What do I do at this point? Is it beyond my DIY ability to fix this thing? Do I need to call in a Pro? What else do I check?