Heater HOT no temp control

[Ruffinit]

My 96 Ranger has had this issue since I've owned it. You can turn the heater/blower to Off and it turns off. No air, no heat.

In any other position it will cook you out of the truck; doesn't matter that it's AC or any of the venting positions. No control whatsoever on the temperature; it's HOT.

Primarily it's my winter truck, but I do 4x4 with it and I do tow with it which means my wife is the temperature control and it is starting to bug her which of course bugs me... Suggestions?

 

[Earl43P]

You have a Blend Door stuck.
Use "Ford Blend door" as your search terms (even on Google) and you will find a LOT of info about Ford blend door problems.

Like this one: http://www.conceptualedge.com/blend-door/

 

[Ruffinit]

Based upon Earl's suggestion I Binged it and it came up with quite a few items. This isn't just a Ranger or a Ford problem.
Basically what happens is that on the top part of the pivot shaft where the motor connects to the blend door the plastic gets brittle. When the plastic gets brittle it will sometimes break which causes the door to do whatever the door wants to do.

I kept coming across a company called HeaterTreater which has a kit to replace the blend door with one they manufacture out of steel with a steel pivot rod. I read up on them, watched their video of the repair process and then based upon that I did a little more troubleshooting.

What I didn't want to happen was to go through the expense of buying the kit and the labor involved to find out it was something else.

Based (again) on the video, I pulled the blend door motor out of it's place and dangling it from the wire harness, I turned on the truck and adjusted the temp. By watching the motor move clockwise and counterclockwise I proved that the motor and the temp controls worked. I therefore concluded that the last thing that it could be was the blend door pivot shaft was broken. You can stick your little finger into the end of the pivot shaft.

So I logged onto www.heatertreater.net and found the kit for the Ranger/Explorer. The kit is $119 plus $10 shipping. The kit comes with paper instructions, the rotary bit for cutting the bottom of the plenum box, metal tape and the door. All you need to do is supply the labor, Dremel and patience.

I ordered the kit and received it three days later (comes out of Texas I think). Went out and had it in the truck in two hours. I did break the bit off but the resultant 3/4 inch length was better than it being 3" anyway. It isn't as easy as the video, but the instructions do state that it isn't easy, it takes patience. The most difficult part was getting the original door out of mine because the top part of the pivot shaft wasn't totally broken off so the door was still fully in place.

I cannot believe that after 3 years of hot (on), cold (off) temperature adjustment that it is so much nicer to drive with this fixed.

 

[Andy D]

The Rat doesnt have AC, just heat and fresh air. I imagine it uses either vacuum ,or even better, a cable to shift the door. Anyhow, it works very easily.

 

[Ruffinit]

The '93 to '08s use the same motor for adjusting the blend door and actually the same blend door. Now they may all use vacuum to adjust airflow for the heater, vents, defrost, but the blend door is actually what changes the temperature. It blends the hot air with the outside air.