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Mark Patrick
Mark Patrick,
Category: Medium and Heavy Trucks
Satisfied Customers: 6
Experience:  Head Mechanic at Estill Wood Products
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2012 Mack cabover trash truck chassis. A/C works

Customer Question

2012 Mack cabover trash truck chassis. A/C works intermittently. A week, day, one hour or not at all. No fan, no light, nothing. If you wait ............ it may come back to life but, then fails again. Wait .........it may come back on.
Submitted: 3 months ago.
Category: Medium and Heavy Trucks
Expert:  Mark Patrick replied 3 months ago.
Just to rule out the simple things first, I would recommend checking the trucks wiring at the switch, the resistor and blower motor. The easiest way is to have the truck running, the A/C on and taking the individual wires and do a wiggle test. If you wiggle one and the A/C starts working then you have found the problem. Being as how your blower is not blowing at all, we can rule out your low and high pressure switch and compressor. If your wiring checks good, undo the wires at the blower motor and shoot 12 volts to it. If the blower cuts in and out or doesn't work at all, then that's where your problem will be.
Customer: replied 2 months ago.
Sorry it has taken so long to get back to you. I just had to wait until the system failed again to run diagnostic checks. Turns out there was a funky resistor . Why that would shut down the whole system is beyond me. ( damn electronics)