Heater blows cold air on 1992 GMC Yukon

Is there a heater water control valve and how do I replace/check it? Where is it?

by in Geyserville, CA on February 20, 2009
1 answer
ANSWER by , February 20, 2009
First of all, make sure the coolant level is OK, and the engine is reaching normal operating temperature. Your vehicle has a temperature blend door, and it is activated by a little electric motor called an actuator. Check out autozone.com for instructions!