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Q: Ac compressor clutch isn't engaging on high fan speed setting while it engages on the prior three fan speeds which are all slow.

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I have a 02 Mitsubishi Lancer ES. My ac compressor will engage the clutch when the fan speed setting is at 1 2 3 and when it is on the high setting which is 4 the compressor clutch disengages. I can have it on 1 2 3 and switch it to 4 the vents blow cold air for about five seconds or so before it hot air again. But with that being said the 1 2 and 3 setting don't work and all three don't work and setting 4 is high. So I either have no blowing air or high blowing air. I've done some research and I do believe this is a bad blower motor resistor. But would the bad resistor have anything to do the the ac clutch disengaging on my high fan speed setting? Or what is at fault?

My car has 136000 miles.
My car has an automatic transmission.

The blower not working is most likely due to a fault with the blower resistor. When you go to high blower speeds the A/C may disengage the compressor if the cycling switch cycles or the high pressure switch gets over pressurized, shutting the compressor off. The first thing to do is to get the blower working correctly then test the A/C pressures using A/C gauges. If you’d like to get this fixed, consider YourMechanic, as a certified technician can diagnose your A/C issue and fix it accordingly. Good luck.

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