Heat blend door stuck

[emingin]

Hello all,

Been looking on here for a couple weeks, ever since buying a 98 4 door blazer. Lots of good information here.

My heater is stuck on, and the climate control doesn't do anything. Researched a bunch of posts on here and thought it was the actuator motor. Got to it the other night and it appears fine. Gears are not cracked, and the climate control makes the gears spin.

Figured I'd try to move the blend door by hand before I put the actuator back on. Can't budge it. I believe I should be able to open/close the door by hand, and it shouldn't be difficult to move. Anyone know?

I'm told the heater core was replaced right before I bought it. I'm wondering if something was installed wrong and has the door stuck. Looks like I'll be getting up close and personal with the dash removal proceedure!

[jdmccright]

The door is operated by a powered servo motor...it won't move easily because of all the step-down gears that are used. If you do try to move it forcefully, you could break a gear tooth. I would try to remove the servo from under the dash and open it up to see if the gearing isn't broken. I've had an instance with my Vibe where one tooth was only partially broken...it was still attached and "laid-over" causing it to be jammed.

With the motor removed, you should be able to check the door itself for any sticking.

Hope this helps!

[emingin]

Here's an update: Turns out when the heater core was changed, one of the bolts that goes through the firewall made contact with the blend door, locking it in place. If we figured that out first, we could have fixed it without removing the dash!

Oh well, all is good now.