99 with No heat

[WillR]

Helping out my Brother today, he has a 98 or 99 with a heat problem

Blower motor works fine.

When you move the control that changes what vent the air comes out of, air flow changes correct (no vacuum leak)

Ford guy said "its got to be the valve that shuts off the water flow" $38.00 later, still no heat.

The heater hoses are hot going in, and out of the heater core.

Short of tearing the dash apart, The temp adj. knob must change a door that mixes cold air, and hot air that flows across the heater core. Looking on top of the heater/AC air box, behind the glove box it looks like there is this white box bolted to the top of the heater box, and the wire colors seem to match those on the back of the temp controler. Am I on track here? does this control the air flow over the heater core?

Thanks in advance.

 

[EliteConcept]

so you can change where air flows to (vents, floor, defrost) but you can't get it warm. only cold?

maybe his T-stat is bad?
also they had a enormous problem with the blend (red blue) dial...i guess they have a pin that is easily broken..

but short of that i don't know
hope he gets it fixed soon winter is coming fast!

 

[WillR]

Yes, we can change which vents the air flows out of (move from Defrost to Heat, etc), so all those vacuum motors are working.

Yes the t-stat is good. In fact just sitting idle, the heater hoses both in and out of the heater core will burn your hands there so hot.

I did read on the internet about either the blend motor is bad, or the blend door is cracked. The blend door repair includes a complete new (updated) heater box, and 6.2 hours of work.

Can any techs out there confirm that the blend motor is that white box mounted on top of the heater assembly, about 1/2 way between the RS and the center (with 3 or 4 wires going to it if I recall) And is the 2- 1/4" bolts seen in the front the only 2 that hold it in

Does anybody have a factory manual that shows a test procedure for the blend motor, and electrical pinout for that connector so we can see if its a control knob problem or motor problem.

Hope I am not asking to much
Thanks

Originally posted by EliteConcept
so you can change where air flows to (vents, floor, defrost) but you can't get it warm. only cold?

maybe his T-stat is bad?
also they had a enormous problem with the blend (red blue) dial...i guess they have a pin that is easily broken..

but short of that i don't know
hope he gets it fixed soon winter is coming fast!

 

[sakirfp]

I have the exact opposite problem. Mine will not blow any cold air. I wonder if we have the same issue...

 

[WillR]

I just found more information then I wanted. Do a search on this site using Heater Blend Door.

Anyway, sounds like this is the problem I have, the blend door is stuck in the closed position.

Here is what I plan to try to fix it. First I will remove the blend door motor, and see if its working. See if the blend door can be moved by hand.

If blend door is stuck, I will cut a hole in the heater box so I can move the door to the heat position (this hole info will be found in the heater blend door search)

We will get a Heater control valve that goes in the heater hose line from an older car/truck, one that uses a cable. Mount the other end of the cable with a knob on it inside the Exp., you control the heat temp by moving this knob on the control cable. It worked for many years on older cars/trucks so it will work on this one.

Originally posted by sakirfp
I have the exact opposite problem. Mine will not blow any cold air. I wonder if we have the same issue...

 

[sakirfp]

http://home.earthlink.net/~kandc1/ford/blenddoorfix.html

Blend Door Fix....

It has great pictures and everything...

 

[WillR]

thanks! Just printed it out and will perform this operation this weekend.