Thread: a/c question
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Old 06-05-2010, 03:24 AM
Davescort97 Davescort97 is offline
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Re: a/c question

Welcome to AF!

The blend door actuator is vacuum controlled. If you have a vacuum leak the door defaults to the defroster setting. Set the A/C on a normal setting with the air coming out of the dash vents. Starting at the vacuum source pinch off the hoses one at a time. When the A/C goes to the defroster vents this is the line you want to trace for leaks. If a vacuum hose was off completely the A/C would go through the defroster vents all the time. Because the A/C goes to the default under acceleration is an indicator that maybe the vacuum canister is leaking. It is supposed to hold enough vacuum to operate the system under a load. In addition it could be a leaky hose or a hole in the vacuum motor diaphragm.
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