Actuator Issues
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Joined: Oct 2014
Posts: 82
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From: Marietta Georgia
Actuator Issues
I just received my new blend door actuator. I plug it into the car to test it. The arm will only move maybe a quarter of inch between selections on heater controls. It is doing the same ing the old motor was doing.
What could cause this issue.
Thanks
What could cause this issue.
Thanks
Race Director
Joined: Apr 2002
Posts: 10,036
Likes: 346
From: Anaheim CA
The blend door motor needs to be calibrated. You do that by removing and replacing the CTSY/CLK fuse ('86 through '89 -- you didn't tell us the year of your car. I don't know what fuse it is on 1990 and later cars) so the HVAC system forgets all its settings. Then turn on the ignition. The HVAC system will move the motor to the full cold position, the full hot position, and then set it to the position that corresponds to the temperature on the control head. This procedure takes about 15 seconds. I don't know if it will work correctly with the motor not attached to anything because I believe it needs to stall out when it hits the maximum hot and cold positions.
The motor is operated by the HVAC programmer, which is located above the gas pedal on the firewall. If the motor does not work correctly, then there is probably a problem in the HVAC programmer. Likely suspects are the two 140 ohm resistors that control the motor direction. They frequently overheat and either burn up or cause their solder connections to go bad. The HVAC programmer was changed quite a bit in 1990, so if you have a later car then the above may not be valid.
The motor is operated by the HVAC programmer, which is located above the gas pedal on the firewall. If the motor does not work correctly, then there is probably a problem in the HVAC programmer. Likely suspects are the two 140 ohm resistors that control the motor direction. They frequently overheat and either burn up or cause their solder connections to go bad. The HVAC programmer was changed quite a bit in 1990, so if you have a later car then the above may not be valid.
Last edited by Cliff Harris; Dec 13, 2014 at 03:41 AM.
