The two electric actuators on the ac/blower box

[Jean]

What would cause these to constantly run? They open/close the flap for air circulation, but would the lack of a/c switch cause these to constantly run?

Thanks

[DaveSmed]

Constantly run as in....?

They are constantly powered up with the ignition on and usually work against the flap they actuate. They are equipped with a PTC so they don't get too hot due to being on constantly.

[Jean]

Ok, I wasn't sure if what I was seeing is normal. I had the actuator bar disconnected and it kept on doing a full rotation until it hit the side of the box. I figured this behavior wasn't normal.

[DaveSmed]

Oddly enough, it is. I was scratching my head too at first.