heater not working

[emsxp]

1999 4wd V6:

Heater stopped working. A buddy of mine flushed the heater core and checked it. He said everything looks fine and mentioned that the problem might be with the control panel (electronic/ wiring)?? It was brief conversation and he is still looking into it, does anyone have idea where else to look for the problem. The A/C works fine and the heater was working last winter. It just blows unheated air when the heater is turned on.

 

[Carguy3J]

Search for "blend door". It's a common problem.

It might also be the heater control valve (if you have one). Follow the hoses (under the hood) from your heater core, from the firewall out. They should be connected to a black "thing" with multiple ports and a vacuum actuator on it. That is the heater control valve. It stops hot coolant from circulating through the heater core, when Max A/C is on, for colder a/c. Do a search for "heater control valve"

If you have the electronic temp control, there are also issues with those. Try searching for "EATC".

 

[emsxp]

problem solved, bought a blend door actuator...located behind the glovebox.