I have an interesting problem. My 2001 E350 van's rear A/C is not working. Front A/C is fine. Regardless of front control position for rear, heater stays on all the time unless I turn it off with the rear control. No air is blowing from the A/C vents, only from the heater vent. This isn't a big problem right now, but will soon be an issue. I use this van for my sales route, carrying a lot of temperature sensitive snack products.
I don't have an owners manual, and the Haynes manual has no info at all regarding the rear A/C.
I'm open for suggestions!

 

This is the factory-installed rear heat-A/C system, not an aftermarket or converter installed unit? Haynes manuals aren't that great for anything specific like your rear A/C. Generally I don't have high regard for them for this very reason. There are alternatives to those types manuals if you'll be DIY on your van.

Here's the vacuum diagram for the factory rear unit--from the Helms/Ford factory manual:

Here's a few electrical schematics for the heater & A/C system: Pictures by JWAPhotos - Photobucket Look around at the other albums too---might be something useful for you there too.

Initially it sounds like you have a vacuum issue at the rear unit not allowing the rear blend door to open. Does the heat from the rear unit change with the position of the temp control up front?

Also you can post this in the Cooling, Heating, Ventilation & A/C Forums---lots of specific information guys there too.

 

Thanks for the info JWA ! This is factory rear air/heat. Temperature does not change at all. No air is blowing out of the roof vent, just the heater vent on the drivers side. Rear control has no effect either, but it is simply a fan control. When I noticed this problem I had the A/C on high, using front controls for the rear. Good cold air from the front vents, HOT air out of the rear.
I think I will follow your suggestion and post this in the A/C forum as well. Thanks again.