Q: air conditioner blows cold, then warm

asked by on August 22, 2017

I have done a ton of research on my Honda and spoken with mechanics and I have completely ruled out this all being on the compressor.

In the morning my Civic blows cold air until I begin accelerating fast. If I keep the speed at about 30-35 and the rpm around 2 the air will blow nice and cold, anything after that it will start to blow warmer air, until I release the gas or slow down, then it will go back to nice and cold. If I accelerate too long it will completely turn off the compressor and I will not get cold air for the rest of the drive, no matter how long or short it is. When I get to work, and leave my car in the lot all workday, the AC will work until I accelerate again to get on the highway.

Is this an issue with the high pressure being overcharged? I have replaced the relays, checked the freon level (on the low pressure side), and checked the fans.

My car has 118000 miles.
My car has an automatic transmission.

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You might be on track about the system being overcharged. But that can only happen if the system was recharged and then too much refrigerant or oil was put in. But there are other reasons why the high side pressure might be rising and shutting down the compressor. Dirt in the condenser might be a problem, or there might be a restriction somewhere in the system. It could also be that the evaporator is icing. If the AC is working too well, and the thermal limit switch doesn’t shut down the compressor at the right time, Ice will form on the evaporator and strangely enough, that makes the AC blow warm air until the ice has a chance to melt. But all of this is speculation. The thing to do is to contact Your Mechanic about having a technician come out to your home or office to check out your AC system and let you know what it will take to solve it.

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