Bohemian

Does anybody have the GM OEM Part Number(s) For 82-92 Heater Blend Door Actuator?

And or a Dorman or related aftermarket cross-reference part number?

I've seen various AC Delco & Dorman Heater Blend Door Actuators out on the internet but none of the fitments mention anything other than pickup trucks that span the same time frames.

I gotta think that GM would have used the same heater blend door actuator in more vehicles than 82-92 Third Gen Camaros & Firebirds ?

thanks in advance.

Vader

The temperature blend door on a ThirdGen is operated directly by a Bowden cable instead of a vacuum or electrical actuator motor. Those were not used until much later. The cable assembly is no longer available as a part number, and can be adapted from a universal part.

It is common for the lever on the blend door to break or disconnect from the pivot post.

eseibel67

Digital dash GTA's use an electric blend door actuator, just like every modern car does. Not sure what type of motor might fit in there as a replacement though.

Vader

Good to know. I've only toyed with the lowly TAs, IROCs, and TTAs which have the cable. As I recall, the '91 GTA I worked on also had the cable, and I was right there below it repairing a hacked-up aftermarket radio installation (and injectors, exhaust, frozen brakes, etc.).

Was the full digital dash an option? I'm guessing that Berlinettas might also have had that feature.

If there is a part number on the actuator it might be the best lead to finding a replacement. If it's like most other actuators it might be repairable. If the gears and motor are intact the feedback pot can be cleaned and the often-failed L2722 dual op-amp can be replaced to restore it (about 60¢ at DigiKey or Mouser).

EDIT: I just checked for grins. It seems the price has gone up to a whopping 77¢ - Better hurry before they break the $1.00 plateau (ON-Semi Part Number TCA0372BDP1G).

1984_El_Camino

I found this old thread while working on the driver side heat/AC blend door of my 2000 Buick Regal and ordered a new cheapy actuator along with both types of the L2722 and TCA0372BDR1G motor driver IC's (not expensive!) to repair my original actuator which is probably better quality than aftermarket. Everything internally appears intact, so I expect I can repair it by replacing just the IC. In my case, the DC motor will move in one direction but not in the other as it should, most likely the IC is defective.
Found the ACDelco youtube video for centering the actuator before installation, some techs like to test the part prior to install. Well, mine's not exactly easy to access being up inside the dash, so I agree!
Test Procedure:
Pin 5 +10v (GMAC youtube video shows using a 9v battery)
Pin 7 - Ground - Motor should move "forward"
Pin 6+7 - Ground - My motor doesn't move "backward" as it should, sometimes briefly but not often.
Result - Defective motor driver IC (8-pin IC)
This test is independent of the potentiometer, probably my potentiometer is okay. note: Potentiometer must be clocked centered with actuator output spline centered (FWIW), to about 4.4K Ohms either side of center wiper to achieve potentiometer center position.
Plan to update if/when my IC's arrive.