CBSTANG

I am pretty sure this isnt normal, but my ac compressor will constantly go on and off while I have defrost on, and it is turned all the way to heat with the a/c button off(not lit up). So just wondering if I should just take it in for a waranty fix or is it some sort of easy fix.

hammeron

i vote for warranty fix

aircare84

Read owners manual, air conditioner is auto turned on when u select defrost mode. Been this way for a few years now with newer cars.

CrazyAl

This is not unusual.

The A/C compressor sometimes runs with the Defroster on (even with full heat), in order to pull moisture out of the interior of the car. It's part of the defrost function.

ski

Also, the a/c compressor turning on in the defroster mode keeps the seals in the a/c system moist during the colder months when the a/c is normally not used for cooling the car's interior, which helps to prevent leaks.