99 Windstar rear heat problem

My rear heater fan blows great but it only blows cold air. My front heat works great on all settings.
Can someone tell me how the heat makes it to the rear?

Thanks

I had a similar problem, but mine was intermittent. I followed this board's suggestion by checking the coolant level. It was low. I filled it, and since then, my heater works GREAT!

:thumbsup::thumbsup::thumbsup::thumbsup:

The heat gets there by coolant lines to the rear heater core. Blower moves air over core to give heat. A blend door moves to direct air over the heater core for heat or the evaporator for cool. If you look under driver side of vehicle, you can see them.

As xamper said, top off coolant.
Could be blend door actuator not working
Could be the rear control switch located on the front dashboard
Could be clogged heater core (doubtful)

Here is when I had all heat/No AC in the rear unit...

http://www.automotiveforums.com/vbulletin/showthread.php?t=426908