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Brian Wise

Mac cxu613 fan clutch

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Hello, my name is Brian and am an a/c mechanic. I have a customer with a 2015 cxu613. The problem im having is with the fan clutch not engageing at all allowing the head pressure to sky rocket. I have ran the truck for at least 30 mins and have never seen fan engage. I do have 12v going to it but not sure which wire should have the 5 v computer reference signal. I believe im dealing with a bad fan clutch. Anyone have input that may be helpful to me?

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The easiest way to check to see if the fan is capable of engaging is to disconnect it from the engine harness and run the engine over 1000 rpm. The fan should fully engage in around 10 seconds, if it doesn't replace the fan drive. Loss of voltage triggers a limp home mode, keep in mind the fan drive will rarely fully engage during normal operation 75 to 80% is normal.

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