'03 E350 Sportsmobile heater not working

[SierraHawk]

Front A/C works and all of the vacuum controlled "motors" and blower fan work but the heater "temperature blend door" will not open when the settings are on for hot air.

This assembly is located under the dash on the passenger side of the van just above the passenger's feet. I've removed the heater core cover. The heater core is exposed. It is not clogged with dirt or debris. I can also see the "temperature blend door" in the center and a vacuum controlled "motor" on the right side of the heater core housing.

Everything but the "temperature blend door" works. I can pull the "blend door" open about a 1/2 inch with my fingers but it snaps closed when I let go. I can also see the "vacuum motor" and the rod on the right side of the housing. The "motor" works when I turn the dial to OFF. There is little room for me to see the mechanism that opens and closes the "blend door" but nothing feels like the arm or rod are lose.

I want to avoid pulling the heater core. Any suggestions appreciated.

[SierraHawk]

Left out a relevant point: The heater core is hot when the engine is running.

[moorefc]

Do a search on air conditioning blend door or vacuum reservoir. There are lots of good posts on how the system works...Most common for the vacuum reservoir in the heater box to leak. Solution is to bypass it.

This may get you started...
https://www.sportsmobileforum.com/fo...ode-31097.html
Cheers

[kbeefy]

If you have dash air you vacuum is probably good.
The vacuum actuator snapping closed when you force it is normal.


It sounds like everything is functioning, are you thinking the linkage is stuck or broke?