2000 V10 excursion heat and AC problems

[big_rooster]

have a 2000 v10 excursion the ac doesn't turn on the clutch and only the rear heater works. No heat in the front of the excursion. If you cycle the control panel it will redirect the airflow just no heat. I pulled the vacuum line off the max ac bypass and its not closing off the heat to the front. I am stumped.

 

[CHPMustang]

I want to guess low coolant level or plugged heater core. Can you verify that hot coolant is indeed circulating to the core past the shutoff valve?

 

[big_rooster]

nope but i'll go check that later its to cold now just find it stage to have heat in the back and not the front.

 

[CHPMustang]

If the vacuum actuated shutoff valve is stuck closed even with vacuum hose removed then no coolant at all will flow to the heater core.

The front shutoff valve only works for the front heater core,the rear heater core has hot coolant running to it all the time regardless of heater/AC control settings.