Q: White foggy smoke getting out of my AC vent

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My air conditioner was working properly then all of a sudden, it stopped working. I thought it was a Freon issue. I went to see a mechanic. After he puts in the Freon, the compressor did not kick in. He did a compressor check. The compressor starts working. Apparently, the AC switch on the dashboard had failed. He used the switch for the blower to turn the compressor by running a connection to the compressor relay. After all this maneuvering, the AC starts cooling. However, after working for a little while, I see white foggy smoke getting out of the ACC vent. Then, it stopped blowing cool air. I turned off the AC for a while then turned it back on. The same situation reproduced. It cools off for a while then that white smoke is back again. I noticed also that the high pressure and low pressure line are very cold. What might be the issue?

My car has 134000 miles.
My car has an automatic transmission.

Hi, thanks for writing in. I’d be happy to provide my thoughts on this. The first problem is that the connections the mechanic did is not allowing the AC to cycle out normally and will cause an over pressure of system and it freezes the evaporator. I recommend having the system properly diagnosed to find out the real reason the compressor will not come on. Most likely the AC compressor module is bad and needs to be replaced.

If you would like help, consider having an expert automotive technician from YourMechanic come to your home or office to inspect and diagnose this issue for you, and make or suggest any repairs as needed.

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