Has anybody ever replaced the HVAC Programmer?

[secondchance]

Great to hear you have zeroed in where the issue was.

[dredgeguy]

Progress is a good thing! Let me know if you need another pair of hands.

[Roadster]

Originally Posted by QB93Z

Then I determined that the vacuum tubing between the plenum and the Programmer may have been kinked behind the Passenger side hush panel.

Jim, you lucked out on that one, no need to remove the HVAC programmer is a big plus!!!

[QB93Z]

I received the Heat Blend Door Motor that was supposed to be for '93-'95 that I bought on eBay. I installed it in the car with confidence that everything would work properly.

Well, I have the same symptoms that I had with the Heat Blend Door Motor from the 1991. When the controls are set at 90 degrees, (calling for heat), it blows cold air out the lower vents. When the controls are set at 60 degrees, (calling for AC), it blows hot air out the AC vents on the dash.

I suspect that the motor that the eBay dealer sent me is not really the late model version.

Pictures to follow.

Jim

[QB93Z]

In this pic, top is the controller from my 1994. The corrosion from the AC condensation has damaged the small motor. Below it is the motor from the 1991.



There is a difference between them. The wiring to the motor is reversed:






I swapped the motor leads to reverse the direction and tried it in the car again. The blend motor appeared to run in the correct direction, but it only moved a small amount then stopped. I believe that the unit has a position signal that goes to the HVAC Programmer. So that signal has to be reversed as well.

Jim




Sent from my iPhone using ZR-1 Net Registry

[QB93Z]

Both the 1994 and the 1991 unit have the same GM part number: 16124952

Does anyone know how to identify the correct version in the parts sources?

Jim


Sent from my iPhone using ZR-1 Net Registry

[-=Jeff=-]

did you disconnect the battery before putting that assembly back in? if not do that for a minimum of 30 seconds.. then try again. Blend door will calibrate and then you can control it

[QB93Z]

Originally Posted by -=Jeff=-

did you disconnect the battery before putting that assembly back in? if not do that for a minimum of 30 seconds.. then try again. Blend door will calibrate and then you can control it

You are correct, and I forgot to do that the last few times I put the unit in. I will try it.

Thanks, Jim

[S.hafsmo]

Did the 30 sec recal. help?

[QB93Z]

Originally Posted by S.hafsmo

Did the 30 sec recal. help?

No, I still had the same symptoms. I have been retracing all my steps in this drawn out trouble shooting process. Now I am wondering if the wiring harness from the main harness to the Heat Blend Door Motor makes a difference. It occurred to me that I have been using the harness from the 1991. I have gotten busy with other projects and haven't had a chance to test that theory yet.

Jim