94 E150 5.0L w/ rear heat
I got the heater core out this weekend and have much of the dash apart to get at the controller. I have a couple questions.

1) Which is the blend door? There is a horizontal door just above the heater core, and a vertical door on the firewall between the core and the footwell. Any other doors I need to look for?

2) What's best way to diagnose vacuum leaks/control problems? Chiltons manual has no diagrams for the vacuum lines from the controller to the doors, etc. I have a vacuum pump to apply vacuum.

3) On my van the air feed to the drivers side floor does not seal up to the heater core cover. Is this normal, or am I missing something?

Thanks
Scott

 

The blend door allows cool air and hot air to mix. So the door that enable this would be the one. I don't have the manual on the 94.

A vacuum pump could tell you if the control valve is bad.

I've seen other people post that the heat on the floor does not balance out.

What kind of problems were you having that you suspect the vacuum system?