HVAC blend door motors (Page 1/2)
donuteater306 OCT 04, 01:41 AM
Both blend doors are working on my 87, but both sound like they're laboring or struggling to move. Any suggestions on how to lubricate them?
Gall757 OCT 04, 09:17 AM
Lubrication may not be advisable... What usually happens is the foam edges on the doors fall off and get tangled in the works. They have sticky-tape foam insulation around the edges like the stuff you buy for your doors and windows in your house...(but smaller). The problem is that you have to take the IP apart to get to them.

[This message has been edited by Gall757 (edited 10-04-2015).]

f85gtron OCT 04, 10:33 AM
You can access them by removing the center console and heater tray next to the accelerator pedal. They Unbolt/screw and never had one apart, but looks like the case can be halved by removing screws or rivets....kind of like headlight motors.
Low voltage and amps can make them struggle too.
theogre OCT 04, 10:38 AM
The entire dash is remove to fix binding doors.

Might be normal... The motor does make noise to start.
Then add the motors are directly mounted to the AC/Heat box that acts as sound board to amplify the sound. (Same thing as violin etc make string sound allot louder.)

Worse, Mix motor is on big flat area of the AC box, right behind the radio, and Nothing to adsorb the sound. And mix motor controls 2 doors too so does more work.

------------------
Dr. Ian Malcolm: Yeah, but your scientists were so preoccupied with whether or not they could, they didn't stop to think if they should.
(Jurassic Park)

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theogre OCT 04, 10:54 AM

quote
Originally posted by f85gtron:
You can access them by removing the center console and heater tray next to the accelerator pedal. They Unbolt/screw and never had one apart, but looks like the case can be halved by removing screws or rivets....kind of like headlight motors.
Low voltage and amps can make them struggle too.


The motors screws and connector are fairly easy...
The door arms and clip the doors are attach to are a giant pain. Worse when you drop them inside the box.

The motor have a varistor/"MOV" in series (Small gray disk) on AC/Heat controls. You can't trust a meter at motor connect to get volt reading and mean anything to most users. You need data for the varistor to know what GM did and little to none info is available.

But check the control board for loose/crack contentions. Crack solder joints can make problems. Usually make intermittent connections etc.

[This message has been edited by theogre (edited 10-04-2015).]

donuteater306 OCT 05, 12:48 AM
Thanks guys. Luckily they're both still working, was just hoping that there would be a simple way to fix the creaking sound as the motors are moving. Best to just leave well enough alone.
sardonyx247 OCT 05, 05:10 AM
To be correct the "blend" door is hot to cold and on a cable/wire, no motor.
I know what you are talking about though, the vent, to floor, to defrost, to A/C etc, just saying.
donuteater306 OCT 05, 03:41 PM
Nah, my Fiero is a one-of-a-kind with factory electrical blend door. Hahahaha, jk. However, the next time I'm behind that dash I'm going to spray the pivot points for those doors.
theogre OCT 05, 05:12 PM
I just didn't care about exact name of door... Correct names are Mode door actuator runs 2 doors (PN 3052051) and Recirculation door actuator runs 1 door (PN 3052050). (PN stamped on box side.)

Note that the two motors look the same at first glance but are different electrically. Big gear inside has connects that open/close at points AC control head call for.

Correction: Thermistor, not Varistor in my post above.


quote
Originally posted by donuteater306:
Nah, my Fiero is a one-of-a-kind with factory electrical blend door. Hahahaha, jk. However, the next time I'm behind that dash I'm going to spray the pivot points for those doors.


That can get you more problems in the future.
AC/Heat box is very dirty to start and Oil/grease holds dirt and will accelerate wear etc problems.
Many oil/grease products will attack plastic.
modsquad OCT 15, 03:38 AM
I have been scouring threads for days and can't seem to find a good solution to obtaining another stinkin motor man. My servo motor continuously buzzes like a nagging wife that won't rest until I hit the off button. I've heard one of the fiero distributors sells used ones but somebody got the wrong one sent to them and it was broken. Sooo, if anybody has an extra working unit lying around or a simple mod, lmk. Thanks.
Sincerely,
Magoo