loss of temperature control

I've recently lost the ability to control the temperature of the air blowing through the HVAC system. The heater core gets warm, and the A/C compressor still kicks on. I suspected a bad air mix servo, so I removed that. While doing so, I noticed that one wire to the plug appeared to have been broken, so I repaired that. With the servo off, I can adjust the flap manually to adjust heat temp through the vents. I replaced the air mix servo with a new one, but it still isn't working. When I plugged in the new air mix servo, it rotated to one position, but wont respond to commands from the dial any more. Help!

 

At some point, I know @Dm93 post some pictures on this subject.
In that post, I also believe we discussed how the servo operates.

I will see if I can find the post.

 

The servo wires should be:
Pink wire (Pin 4) Ignition power (battery voltage with key on)
White/Black wire (Pin 1) (Ground)
Red/White (Pin 2) control (should be 0-12v based on the position of the temperature selector knob (12v with the knob at full hot and 0v with the knob at full cold)

Check your voltages at the servo and see what's not correct.

It sounds like either you have a defective servo, the control head has failed, or you have a broken/shorted wire.

 

Thanks, Dm93. This is very helpful! I've been able to determine that the blend door actuator itself is still good, but I had a broken wire on the plug going into it. In my case, it was white/black wire at pin 1 (I think). If I wiggle it, I can get the servo to work. I tried repairing the connector, but it seems to be shot. Is there any way to order this pigtail, or am I going to take my chances with a junkyard?

 

Toyota typically doesn't sell pigtails, they sell the blank connectors and the pins separately and they aren't cheap.
Finding one in a salvage yard would be cheapest if that's an option for you, not everyone has a salvage yard nearby.
If you can solder you may be able to de-pin that wire and solder it back to the pin.