AND the controls feel like its moving something..it doesent feel like its not moving anything...move it to cold its real cold...move to hot just **** warm...like i said i even made sure the cable was adjusted properly...same prob.
mike

 

You may have to take the heater box assembly out and trouble shoot it from there. Its very possible the mechanism on the top decided to disattach from the actual door that blocks the heater core. I had an old bronco that did that. Was an easy crazy glue fix, just was a real pain taking the heater assembly out.

Hope that helps...

 

there are 2 blend doors in side there.
The cable moves the one. Check to make sure the door is moveing all the way closed. Which will be flapping to the left side. There is a seal over there.
I spent 2 hours messing with mine. but since i cant get my arms in there easly without takeing half the truck apart cause i have air conditioning. I could only get it to close 90% of the way.

I'm guessing this is the problem. Could be a bic pen. whatever.
but taht door has to close atleast 90% of the way to force heat through the heater core. As a matter a fact, mine seems like its putting out less heat already.

 

get one of them heaters you plug into the cigarette lighter.

 

HAHAHA im about to... if i had a real truck instead of this pos ford i wouldnt need a plug in heater......

 

Your right, if you had a chevy youd need a few of those heaters, or a real warm jacket for the push home

 

did you ever figure out your issue ?

 

After 11 years he probably traded or sold the truck by now...

 

My '89 is blowing cold too. I can tell the temperature control slider is working because it goes from freezing cold to lukewarm.

The truck has a new radiator and new hoses to the heater core. Previous owner said they replaced the heater core too, though I haven't verified. I think they did the thermostat, but just ordered the stock temperature 195*F stat, thinking maybe they put in a 180*F thermostat.

Not sure if it pertains to this truck, but I know in some cars you need to "burp" the heater core or trapped air will keep water from circulating. Will do that when I change the thermostat next weekend. That will let me check the water flow too.

Might check the seals on the flapper door too today since I'm off work.

 

Pulling the dash apart would be the last option I tried. Pop the glove box out so you have acces to the heater core box and open it up. Then make sure your trucks warmed up. Turn the heat sector on full hot. Your heater core should be hot. I would suspect it's plugged up. If that isn't it then look at the vacuum lines under the hood that provide vacuum to the heating system controls. There should be an actuator in the back corner of the engine compartment that has vacuum lines running through the firewall (with wires in a bundle) you'll see them inside by the heater core. I had one get brittle and crack awhile back. After replacing it everything worked. Good luck

 

Heater core is smoking hot .. And air is passing through it I can take the cover off and turn on the heater and it doesn't take long to warm the truck up but if I let it blow through the vent system it comes out Luke warm

 

Is there any way I can get to the blend door without tearing it all out just to check see if maybe something has gotten down in there and keeping the door from shutting all the way

 

I'm really not sure about the blend door. Have you tried looking for a youtube video on the topic? I don't think you have to tear the dash apart though

 

Just went through this with my 93. Do the work through the glovebox opening after removing it. Remove the heater core and closely inspect with your hand the blend door. Mine was being held open by a screw and ball point pen. Replaced the core and the heat is very hot now.