Selector switch for changing from floor to dash to defrost doesn't work. Is there any common reason for this condition?
Jun 6, 2009 at 7:57 AM
1997 GMC Safari heater control unit
JEB STUART
- MEMBER
- 1 POST
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Hello, if the actuator doors are vacuum controlled and the vacuum source is lost, it may revert to defrost mode and stay there. The vacuum source, if that is the problem, should be located under the hood. I don't have a vac diagram right in front of me.
Jun 6, 2009 at 9:41 AM
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