Blend Door Revisited

[masapell]

I thought that I would post this to see if anyone has had this same problem. After changing to heat/defrost the other morning I have noticed a motor sound along with a slight clicking noise/light thumping noise coming from the air box under the dash. It sounds like it is the blend door for the heat/ac. It is switching between heat and ac just fine, but it is making strange noises. I am thinking that it is the blend door actuator that is going out. Does this sound like a likely scenario? Does the actuator just slide over the door shaft? Are there gears inside the actuator, or on the shaft? I didn't think that the blend door is faulty, but that it probably lies in the actuator. Thanks in advance for any information.

Sincerely,
Matt

[kahjdh]

Mines bad too. Its just a motor with a worm drive and a position sensor. Dont try to use it when it is off of the blend door b/c it will mess up the motor. There are some posts on here to rebuild it or you can buy a new one.

[masapell]

Well, I looked a little more into this and it is actually the fresh air/recirculating door motor. So, I am to assume that the only way to get to that one is to pull the entire dash out? Or is there some other trick to get to it?

Sincerely,
Matt

[rancherdog]

Did u ever find the solution to your problem? I have a 94 pick up and evertime I trun the truck on and off it clicks for about 20 sec and then quits. I was told it's the blend door but it looks like a bitch to get out. any answers??

[masapell]

I did look into this and asked a mechanic that has replaced the motor on the fresh air door. After talking with him and researching it, I found out that the entire dash has to be removed; a time consuming and costly propostition. So, what I did was wait until the outside air door was closed and then I unplugged the wiring from the motor. Voila!!! Fixed!! If I ever feel like wasting a couple of days of my life, or hundreds of dollars, I will mess with it. Sorry for the bad news!

[doctorhrdware]

It is the AC/Heat control module that is bad. It is the heat / ac blend door that is slamming. If you turn that middle control knob counter clockwise, just a bit, it will stop the door from slamming. I had the same issue with the Wife's 2000 Silverado. Change the control head, and it solved the issue. I believe that it is caused by cold solder joints on the AC/Heating control module or the control pot(not sure if it is or not) for the blend door? I have to toke the module apart and see what type the for the blend door. I have not fixed the one that came out of the wife's truck as of yet. I also need to replace the grain of wheat lamps. Most of the lamps are burned out. Even on the used one that we bought. I am thinking of installing LEDs instead of the grain of wheat lamps. The filament does not hold up like the led can. I need to order the leds first in order to complete the repair. I am thinking of using either blue or white, or possibly red. I want to see which one looks the best. After I am done I will post pictures of all three different LED colors. I will take the pictures at night, so that I can choose what looks the best.

[MT-2500]

Originally Posted by mafzald2

I have not heat in my truck and I need heat for the next few days. I heard you can manually switch over the blend door. Where is it located at?

For help on your problem.
You need to do some proper testing and checking.
First thing.
Best to start a New thead on your problem and give all info.
Give us Year make and model and size and engine and color and mileage.
Auto or regular Heater controls?
Any lights flashing blinking?

Also describe your no heat.
Like no blow no warm air just cold air or no air blow at all?

If just no heat start with checking coolant level in rad and overflow tank.
Is engine warminging up to proper 195 degrees?
Does both or one heater hose feel hot to touch.
Got good engine vacumn to heater controls?
Any recent repair work done to it?