heater core

my wifes windstar stopped blowing hot air this morning. she said there was a humming sound coming from the dash for the past week or so then it stopped and so did the heat. would this be the heater core and if so where is it and how do i replace?

Depending on the year model (?) ... you may have a blend door or blend door actuator issue.

it is a 2000 model. what exactly are you refering to? i have never heard that term. there is not the typical anti-freeze odor associated with a bad heater core.

The blend door opens and closes allowing warm air into the passenger area. The actuator controls the door. The fan blows the air, is it working? Last, the the heater core maybe clogged or restricted and not warming up the air for the heater. To check the heater core, get the vehicle up to operating temperature and then feel the hoses going to the core. They should both be about the same temperature as the radiator hose. If one of the hoses going to the heater core is significantly cooler than the other hose going to the heater core, the core maybe restricted. Is the fan working on all speeds? Need to check that. If the fan is working and coolant is being circulated through the core, the only thing left is the actuator and the blend door. A repair manual should provide you with step-by-step instructions and illustrations.

the fan is working. in fact the a/c works great. it is just the heat that doesn't work.

dadofmultiples -

The blend door is a common problem. Take a look at this thread, or search on 'blend door' for lots of info:

http://www.automotiveforums.com/vbulletin/showthread.php?t=524247&referrerid=396853