Controls stuck on defrost

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May 23, 2010 | 12:57 PM

tri power

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From: Alabama

Controls stuck on defrost

My control was working fine bi level norm etc., now it is stuck on defrost I unplugged the vacuum line going to the defrost actuator it still blows on defrost what can I do to make my controls right?

May 23, 2010 | 01:04 PM

lordmetalz28

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From: hudson valley, NY

Car: 1987 Z28 with iroc-z Package no.3

Engine: 350TPI

Transmission: 700r4

Axle/Gears: 3.73 posi

Re: Controls stuck on defrost

Sounds Like your Vaccum control valve( a/c switch). try taking it out cleaning and re Greasing it up. they dry out over time

May 23, 2010 | 01:04 PM

JamesC

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From: Lawrence, KS

Car: Met. Silver 85 IROC/Sold

Engine: 350 HO Deluxe (350ci/330hp)

Transmission: T-5 (Non-WC)

Axle/Gears: Limited Slip 3.23's

Re: Controls stuck on defrost

Quote:

Originally Posted by tri power

My control was working fine bi level norm etc., now it is stuck on defrost I unplugged the vacuum line going to the defrost actuator it still blows on defrost what can I do to make my controls right?

Defrost is the default. The common problem is vac loss, often at the switch. Stick your ear to the HAVC and listen. You may be able to hear the leak there.

JamesC