1999 GMC Safari Rear Heater

1999 GMC SAFARI
152,000 MILES • 6 CYL • AWD • AUTOMATIC
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CGM
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  • 1 POST
The rear heat does not work any more. It blows cold air. Could this be a rear heater core problem? If so, where is it located and how can I repair it?
Oct 14, 2008 at 9:12 AM
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MIKE 1
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I have a 1986 Safari with the same problem. In my van, the heater unit is located behind the drivers seat and is attached to the outside wall. The heater core is inside this box.

When operating the dash controls for heat, vacuum is applied to a valve located on the passenger side of the engine compartment. It is down very low and can only be seen from underneath. (There are two fluid hoses in this area for the coolant).

I suspect the valve is seized in my vehicle. Due to the vans age, I have not tried to fix it.

Good luck

Mike
Nov 27, 2008 at 7:10 PM