A/C stays cold but less air comes out vents
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Joined: Jun 2003
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A/C stays cold but less air comes out vents
1991 Explorer XLT. Engine runs great, IMHO, and A/C is nice and cold (a good thing in Texas.) When I start it up, and then for about the next 20-30 minutes, a normal volume of air comes out through the vents. However, after about 30 mins, the amount of air starts to decline, though it's just as cold. Simultaneously the noise of air inside the plenum area seems to be getting louder. If I switch from A/C to defrost and back a few times, it often helps.
Is this likely a vacuum issue?
Is this likely a vacuum issue?
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Joined: Feb 2001
Posts: 1,728
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From: Keweenaw Bay, MI
A/C stays cold but less air comes out vents
I have had the same problem several times with different vehicles. If your refrigerant charge gets a little bit low, your evaporator temperature drops below freezing and the condensation freezes on the coil fins, blocking the air flow. Check your low side pressure after it has been sitting for a while and see what your corresponding coil temperature is at a fast idle. If your pressure indicates a temperature below freezing, you need to add a little bit of refrigerant.
