AC blend door actuator problem

I did this tonight before driving home and didn't hear it the entire 25 minute drive back. Afraid to say it's fixed but damn it was nice to just drive in silence without the noise.

 

I've been having issues with my blend door for probably 2 years now. Every winter I manually turn it to full heat and every summer I turn it to cold. I finally bought a blend door actuator from a part-out truck but when it arrived it had a different connector so it would't work. Ive tried all the tricks, turning the knob back and fourth a million times, and opening the actuator and cleaning out the contacts/bending them up for better contact with the wheel.

Then I saw this quote and tried it:

So when I push in (a decent amount) on the temperature control knob then the blend door will turn to the correct setting, and if i continue to push in on the knob and rotate it one way or another slightly the blend door will do the same like the correct operation that it should.

My guess is that its the potentiometer behind the knob that is having issues contacting and delivering the right resistance reading to the blend door. Has anyone pulled the AC control unit and opened it up to get to the potentiometer and clean it up? I've looked at the prices of new AC control heads and I don't want to go that route if the fix can be a potentiometer adjustment.

 

might have luck sourcing a used one from ebay

 

That was my problem exactly. Solder joints between the temp switch pins and circuit board were fractured, and making intermittent contact. Opened up the control unit, reflowed the solder on all the pins with an iron, been working flawlessly for a couple years now...

 

Here's what the little bastard looks like. I've tried to source a replacement with no success. I haven't taken this one apart because its a known good one. I believe it's acutely called in encoder potentiometer.

 

I do this exact same thing on my 98. It might be different but I actually had a part break under there. I reach under there and manually turn it over. When I do it for the heat - holy crap. It's so hot the vent will almost feel like it's burning your hand. lol

 

Yeah I can do that as well if I need to, I can reach the blend door arm from the driver seat. But I would like to have the issue fixed so I can use the AC knob and have the actuator do the work.
Im going to try to dig into it this weekend, Ill see what I find

 

So I have fixed my issue.
Since reading that pushing in on the temp control knob can determine if it is the actuator or the AC control unit I pulled the AC control unit today and did some looking around.

After opening up the control unit i looked at the soldered contacts on the backside, those all looked good. I looked at the knob where it comes through the white bezel and I figured out I could slip in a little washer in between the bezel and where the knob pokes through. This way the added washer would put some pressure on the base of the knob where the potentiometer is which is what solves the issue that i've been having (when i press inward on the knob the actuator turns to the proper position.

In the pics that I uploaded two of them are just opening up the control unit. The other two where i put the washer, and where the washer gets sandwiched between the white bezel and the potentiometer knob.

Hopefully this might help some others out that have determined that it isnt the blend door that is having issues, but actually the AC control knob.

 

Here's a few pics of the inside of it.

 

That washer trick actually worked. I had to do a few modifications to get it perfect. I had to cut the washer in half so it was only pressing on the top half of the actuator. Hey even Jerry’s rig worked

 

I give up, and can’t find any info anywhere.

I recently replaced my mode actuator. once I pulled the old one off, I noticed the blend doors were off track.. does anyone know how to orient the blend doors into the grooves of the turning mechanism?

 

The washer solution from Rucas worked like a champ. I had been dealing with this problem for many years by just switching the air back and forth from hot to cold until it found it's happy spot. I figured the actuator would be the easiest fix and a new blend door actuator popped up on MAC.BID which cost me $4.44. After pulling the old one I plugged it back in, turned the acc power on and watched it hunt around all on it's own. oh well, I installed the new one and searched tacomaworld for another solution and ran across Rucas' post.

Update: the washer worked for a while but the problem came back. I found a suspicious looking solder on the board for the rheostat so i tried to resolder it. The problem is much better but not completely fixed.

 

Do you have a 2006 Tacoma? That's considere a 2nd gen. This is the first gen section.

 

Good call. Not the same at all.

 

what did you clean it with? Electrical cleaner?