AC Problems. Help!
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AC Problems. Help!
Hey all! last week my AC quit blowing cold at idle while sitting in my driveway after working fine coming home from church. I shut off the truck and went inside. when I started it the next day for work it blew cold just fine and did so until today. I was driving in city traffic and it was blowing cold and then after about 15 minutes on the road it quit blowing cold again. after leaving a stop light and accelerating it starting blowing cold again like normal for a few minutes but then quit again. I parked it for about an hour and it didn't blow cold again.
Im left wondering what this could be. I checked and the compressor is not coming on so I don't know if I should check the pressure switch maybe? It doesn't seem like it would be a freon issue since it was blowing ice cold before and quit all at once. The compressor has also made no weird issues and there have been no weird smells or anything from the vents.
the truck is a 2002 F150 4.6L with 245k miles but had a crate motor put in at 150k
Thanks for any help!
Im left wondering what this could be. I checked and the compressor is not coming on so I don't know if I should check the pressure switch maybe? It doesn't seem like it would be a freon issue since it was blowing ice cold before and quit all at once. The compressor has also made no weird issues and there have been no weird smells or anything from the vents.
the truck is a 2002 F150 4.6L with 245k miles but had a crate motor put in at 150k
Thanks for any help!
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From: Utah
Can you hear your blend door moving? Is the compressor on while it is not blowing cold?
I wouldn't doubt it if you either have stripped out gears in your blend door motor, or a broken blend door.
I wouldn't doubt it if you either have stripped out gears in your blend door motor, or a broken blend door.
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The compressor is not coming on while it is not blowing cold. I recently fixed a vacuum leak that made the AC go to the defrost on acceleration. I’ll check in the morning to see if I can hear the blend door moving when I switch to the floor and back and forth. It will be interesting to see if it blows cold tomorrow after sitting overnight too
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From: KY.
Unplug the pressure switch and take a wire and jump the plug, if the compressor comes on it's low Freon or a bad switch in my opinion, if it doesn't still come on it could be a bad clutch coil, bad inside switch, or some other wiring issue. If the clutch air gap gets too wide they can fail to come on, or work for a while then click off. Good luck.
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From: Utah
Yeah, don't worry about the blend door yet. Sounds to me like you are low on R-134A if the compressor is kicking off. Or like JCR said, bypass the switch and see what you get. If it is intermittent, probably low freon though.
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UPDATE: so I start the truck this AM and the ac is working like normal. I am going to borrow some gauges from a friend and see what the pressures are while the compressor is working to see if that would show low Freon. Also it’s currently 83 degrees and 85% humidity. I’m wondering if the outside temp is affecting pressures in the system and when they get too high it shuts off??
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ok had a mechanic friend come over and we hooked up the gauges while the compressor decided to work. The low side was about 40-42 lbs. Not too bad. We put some freon in it to bring it up to about 45lbs. but the intermittent compressor problem still was taking place. we then decided to try the low pressure switch. we pulled it off and jumpered it and it worked! with the jumper in it would cycle on and off as many times as i switched it on the dash. we noticed there was some corrosion on the plug side so we cleaned it and sprayed it with WD40. it seems to be working fine now, but it if acts up again i will get a new low pressure switch.