climate control blend door problem [Solved]

can hear blend door opening and closing all the time just had in for new front hubs with bearings and abs replaced now a/c and heat keeps cycling out vents. i can control what vents it comes out but keeps blowing heat then ac can hear door moving back and forth any suggestions

You might try treating it like a computer...reboot. Disconnect the battery for 20 minutes and make sure the cell phone charger doesn't have a cell phone in it.
Surprisingly enough, there was a guy years ago on the old Wrenchead.com site who couldn't reset the codes on an OBDI vehicle and later found a cell phone on the charger which was back feeding the ECM enough the codes wouldn't reset.

thanks for the reply chris, i disconnected the battery overnight and reconnected still the same. no accessory's plugged in ...blend door just keeps going back and forth. ?? i have to ASSUME the blend motor actuator works if it opens and closes ? was able to disconnect electrical connection at acctuator and it defaulted to the middle. can the computer be reprogrammed or???

Here's some info.
Big thanks to riccbhard and JoshBarber at the Blazer site.
http://www.automotiveforums.com/vbulletin/showthread.php?t=574779&highlight=blend+door

ok just fixed this problem ..blend door was going back and forth searching for right spot to match temperature... moved temp knob back and forth several times then moved temp very slow on all differebt settings and it hit now working. thanks to everyones input

Good work, we'll try to remember your fix.

Our Bravada seems to be having this problem, but having read in several posts about the blend door motor being behind the glove box - I cannot find it. Ours is a 2000 Bravada - is it in a different location on the 2000?

Anyone got pictures of it in place?

following up - I looked again and I can see the two vacuum servos which control the outside air and the outlets. They both work so I know I have vacuum, and they direct the air correctly but no matter what I do I get hot air, so I am suspecting the blend door motor, but cannot see it. I found a picture here of the unit itself but only after removal. All the descriptions I have found says flip down the glove box door and there it is. I see the flasher, a large wiring harness connection, the two vacuum servos and that is about it. It has the automatic climate control if that matters.

I am wondering if anyone reads these posts?

Ok I have found the actuator, managed to remove it (only a half dozen bloody spots on my hands from squeezing hands into where they were obviously not intended to go), disassembled it and found a small crack in the large plasit gear but it was not acutually broken.

I connected it to the wiring connector and it turned on and ran slowly - once. There after it did not move except for about one second bursts and at no specific time.

I back probed the connector with the switch on and got 12+ on the brown wire as I expected after finding a wiring diagram on here. The return wire from the pot inside (forgot the color code but maybe was the light blue) would go from 0 to about 5 volts depending on the position of the large gear.

Before spending the $100 or so to replace it - is there anyone with any other testing I can do to verify that it is really this actuator that is the problem?

I am wondering if anyone reads these posts?


Maybe if you started a new thread about your problem you migh get more responces. this one is titled "solved"

yes, this thread is over 6 months old. a new thread can be started if need be.