Clamp off the heater hose so it's not a factor in reheating conditioned air.

 

I guess I don't have anything to lose at this point. I could just go ahead and cut open the box and take a look. Is it possible the seal around the blend door is bad? I did notice when I removed the actuator little bits of foam. Does that mean anything to anyone? Thanks

 

I had an explorer once that had a very dirty cooler ( by the radiator) with mud / lint/ etc.. It made the unit run a little high on the HI PSI... and it did not cool as well... You might wash out the radiator fins and the AC cooler coils in line with them with a garden hose.. See if anything washes out.

 

Thanks Steve. Great idea. I still keep returning to the blend door in my head. I don't know what else could be affecting the AC and heat. There isn't anything, is there?

 

No........ all they have in common is the blower motor, the duct, and the blend door......... inless you have two SEPERATE problems.

 

Is it possible to have a hole in my duct work? Or even thr blower motor? It's just so odd how this has happened.

 

the blend door #5 routes the cold air thru or around the heater core #17 below... don't matter if the duct has a hole. If air is coming out the vents it has to be going pas blend door #5 one side or the other.

 

So the odds are that it is my blend door. Nothing else could cause a loss of hot air and a loss of cold air. There must be something wrong with it that I can't see from the bottom.

 

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one test that SHO mentioned is to shut off the hot water flow thru the heater. Then if the "cold" air goes around or thru the heater core, it will not warm up.. IF it gets "colder" with the water pinched off, then your door is leaking !

 

Thanks all for the replies. I decided to do a full coolant system flush as a last resort. After completing this I turned on the AC and it seems to be working great. Today it was only 80 though so the test will be when it's in the 90s this weekend. Is it possible that due to poor coolant flow or something that it could cause a loss of ac or heat? Thanks again. And I will try shutting off the hot flow next. Thanks for that tip.

 

Poor coolant flow through the heater core will affect heat only, but not AC.

 

Tonight I clamped off the heater hose and then checked the AC. Blew nice and cold. 42 degrees to be exact. Removed the clamp and checked the temperature again. This time it blew 48 degrees. It was about 75 degrees out when I did this. So not a huge difference but noticeable. I am fairly confident it is the blend door now. Would you all agree? And thank you for the tip on clamping off the heater hose.

 

Update. I cut the box open today and took a look inside. The blend door is in tact and functional. I don't get it. I ran the AC while I had the box open. The AC blows really cold inside the box. However, when I put the cover back on the hole and force the air through the vents the air warms considerably. Anyone have any thoughts or ideas? Completely lost at this point.

 

After sitting and letting the truck idol for a while and feeling around in the box I noticed that one side of the AC evaporater core is warm and blowing warm air. The other side though is ice cold. Does this mean the AC evaporater core is bad or plugged?