1991 Aerostar Front Heater Problem

My friend owns a 91 Aerostar and the front heater don't work. I was wondering what I should check first (most likely the problem) in order to fix it... I've already checked the heater blower motor fuse, so it's not that... would checking for a faulty blower motor be my next best thing to check? what else should I check? Thanks for any help.

StiffyLS

It is probably the Heater Core, feel the Heater Hoses do they get Hot?

Hi I have the same problem but i get heat for about a min then it's cold air blowing and already replaced the heater core so now looking for the most common thing that can go wrong since had to 3 different mechanics and they don't get it either thought someone here might know?? and yes the hoses get hot but we think the outside door is opening when should be closing any ideas??
Please help !!
Sizzz

I also have this problem on a 93 aerostar - I've replaced the heater core (that was a pain in the ass) and the thermostat - my heater hoses also get hot - is there a sensor that opens the heater door?

thanks
Brian

Haven't figured out how to post a new problem...My Aerostar's (1991) heater normally comes on at start up, but when you shut down, it does not come back on till it is good and ready. Time varies. Occasionally, very seldom, it does not come on initially. Seems strange to me, any comments ? I live in CO and the weather gets COLD so this is annoying.

The blend door is vacuum operated if its like other older Ford's. Check for vacuum coming from the intake. Look for a rotary vacuum switch in the dash make sure its getting vacuum. I've changed the vacuum motor on the blend door also.

1991 areostar, heater core replacement, does any one know how to replace the front heatercore?