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Q: The AC stopped working. It blew cold on passenger side only. At same time car was sounding like it was stuck in low gear.

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The AC stopped working. I had it repaired. But, then only blew cold on passenger side. Thereafter, the car started making a noise like it was stuck in a low gear and seemed like it was lagging. Recently, while I was driving the car down shifted on it own the awd and break light on dash came on and then flashed next thing I know the car turns off and all the lights go off. Not sure what is going on with car. Has 115k miles.
My car has an automatic transmission.

A: Hello and thank you for contacting YourMech...

Hello and thank you for contacting YourMechanic. Check the little wheel below each vent to make sure the vent is fully open. The wheel adjusts the volume of air coming out of the vent. The next thing to check for is air coming out of a vent that is not turned on. Check the defroster and also the floor under the dash. The driver side vent is farther away from the cold source and there is much more warm plastic duct for the air to flow to get to the driver side of the dash. When the refrigerant gets low part or the evaporator is colder on one side and as the refrigerant travels to the other end it flashes off the compressor and there is not enough refrigerant in the tubes further down stream to remove heat. I recommend checking the pressures on the system to see what is the high and low pressure. If the system is low on refrigerant, then you will want to check the system for leaks. If the system is good on pressure and has no leaks, then your problem is within the dash vents. They probable came apart within the dash. As far as the lights coming on and the vehicle lagging, either the compressor was putting too much load on the engine or the transmission was malfunctioning and the computer system shut down the engine to prevent damage to the engine. Scan the computer for any possible pending codes and continue with your diagnosis. If you need assistance with diagnosing your a/c or dash lights, then seek out a professional, preferably a professional from YourMechanic to help you with your vehicle.

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