Door blend actuator

Hi folks 2005 Tacoma,

justreplaced the heater cre evaporator installing everything as I think it came out.
The recirculatory button works as the flap moves in or out when button is pushed
The vent controls work, you can see the flaps open and close and feel the air blow in the intended direction
The only thing is the air is hot all of the time, is there something that I missed?
I do not have the system charged yet, could that be the problem?
In other words what is supposed to happen when you change the climate control, does it only work or actuate when the system is charged?

 

Really? That's pretty helpful

 

I guess what I'm driving at is that the climate control only works when the system is charged?

 

You mentioned the system wasn't charged, I am assuming you mean the A/C? If that's the case get it charged and then see if you are having the same issue.

 

A/C doesn't need to be working to blow ambient air. If the temp dial is turned all the way cold, and the air coming in is heater hot, it sounds like the blend door is working backwards.

 

Is there a connector plugged in the blend door? I know I connected the one operating the vent switching, the top one behind the glovebox. I didn't see any connections for the other ones

 

Yes, there are 3 electric actuators. I don't remember which is which, and I can't find the diagram right now. CRS

 

https://www.tacomaworld.com/threads/06-air-mix-servo-stuck-no-heat-solved.454709/

 

OP, take a look at the diagram above by @Muddinfun. The heating control servo is the one labeled "AIR MIX CONTROL SERVOMOTOR". Its on the lower right and below the glove box.

Turn the key to the "ON" position but do not start the truck. Leave the radio off and blower fan off, you want it in to be a quiet and in a quiet place place. You may also want to remove the glove box.

Now go sit in the passenger seat. Turn the temperature dial slowly one way then another. That servo connects directly to a flat plastic flap inside the HVAC unit. The flap in turn is covered with a thin foam piece to seal around the edges. You should be able to hear the servo run its motor and the flap move when the dial is turned full cold, partial, and full hot. It should not be straining or clicking.

I can think of three points of failure for that flap as follows:

If the motor runs but it seems to sound like it is straining or clicking it might be a jammed door. Years ago there was a TSB for that flap IIRC where a substandard adhesive was used to glue the foam to the plastic and the foam would come unglued and jam the flap open/closed. If I can locate it I will post.

Failure point number two may be the servo motor itself. No noise of the motor operating while the temp dial is rotated is bad news. I have had several apart and they are unbelievably fragile inside and use thin plastic gears. I have attempted repairs of the gears with no success.

Finally, a small really thin plastic pin is used to engage the end of the servo motor on a cam to move the heater door flap. I broke one off one time. Frankly, I don't know why they all don't break because they are that crummy. Anyway, if you can hear the motor running but can't hear the flap moving there may be a problem with that plastic pin. You can also look at the end of the servo without unbolting the thing to see if it is moving.

 

Thank you for your help, when double checking everything forgot to put the connector in the bottom of that motor. It works like it should now! Sure is a real PITA to replace that evaporator, thanks again!

 

I would never attempt that job. The steering wheel would be in backwards lol.

 

I have the clicking noise when turning on the "Recirculation" button, like many here. My problem is a chipped tooth on the big white gear inside the HVAC recirculation door actuator. The one that connects to, and operates the blend door.

For those of you that are courageous, you can make the attempt to repair the broken tooth using the super glue / baking soda trick (look it up on YouTube or search the net to see how to mix them together).

I will tell you, it took several tries. I filled in the gap where the tooth used to be and let it dry overnight. This seemed to work best. It needs to dry hard.

Then carefully, using a razor blade at an angle, I worked it back and forth to carve the tooth. I have only just completed the carve and tested it with a 9 bolt battery to make sure the gear meshes and turns in both directions (switch the leads to reverse direction).

Not sure how long it will last in a working environment, but the price for the repair was right!

My .02