Question about Cars & Trucks
Could possibly be a vacuum leak. The blend door actuator controls are usually ran off of vacuum. It is possible that once the engine warms up, even though you have it to heat, the loss of vacuum will cause the blend door to switch positions.
Posted on Dec 26, 2013
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Posted on Jan 02, 2017
SOURCE: 1998 ford f150- heat issue
There is no heater valve on a 1998 ford F-150. The hoses for the heater lead directly from the engine and go to the heater case. PS The heater doors are all vacuum controlled so you might wanna look under the dash for any lines that might be disconnected
Posted on Jan 28, 2009
SOURCE: 1999 Ford Taurus, no heat.
Try checking the two pipes that go into and come out of the heater matrix, is one of them hot? if it is there is an air lock within the matrix, Also is the thermostat opening fully? Sorry i know you said you have changed it twice already but take it out check settings when it should open and close, then boil some water and test the thermostat
Posted on Dec 30, 2009
You just might have an air lock. Try bleeding the system from the heater hose at the firewall. Losen one hose a little, and at operating temp. open slightly to let air out. You will lose some coolant, but just refill the rad. Now, both hoses should get hot.
Posted on Jan 01, 2010
You might have to purge the coolent system cause when you change stuff like that you normally have to bleed the the colent system. So what you have to do is run the car untill your temp gets to 195 degrees the cut the car off and let the coolent drain down and then refill and geep doing that untill you have heat.
Posted on Jan 09, 2010
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