Your right, once battery fully charged the buzzing went away.

I dug into the passenger side actuator first. Moved the drive gear two teeth clockwise and hooked it back up to the power switch. Now when I move from Hot to Cold on HVAC control display, the metal shaft of the actuator rotates when it did not previously. I found no broken gears and everything looked to be in good condition. When I went to reinstall the actuator and bolt everything in, it was a PITA to get back in. I had to readjust the drive gear a little more in the clockwise direction to get the actuator to slide back in its original position.

I tested the temp controls once bolted in and BOOM - the doors now move and cold air blows out when put to full cold. BUT I still have an issue. When moving back to full hot after being on full cold, the door (that blows cold air) does not close all the way, causing the air to be luke warm instead of full hot.

Another odd thing- when resetting the HVAC codes using the DIC, the temp doors on passenger side go to full hot and stay there until I try to change the temp to cold. Once I do and then switch back to full hot, I get the same problem above with the cold air door only closing 3/4 of the way.

When I clear the HVAC codes the Drivers side acts weird as well. The cold air door closes, but after a couple seconds, the cold air door opens back up again and this is its final resting place after resetting the codes. I then change the temp settings to hot and I get no response on drivers side. My next step is to re-adjust the drivers side actuator gears like I did with the passenger. This one was just installed by my mechanic, so i'm hoping this is all I will have to do.

 

Re-Calibrating Actuators

Use the following steps to perform the calibration update:

1. Turn OFF the ignition.
2. Remove the battery positive voltage circuit fuse of the HVAC Control Module (fuse #27).

Important
The module memory will not clear if the battery positive voltage circuit fuse is installed in less than 60 seconds.


3. Wait 60 seconds.
4. Install the fuse.

 

If it was me doing the work, I'd replace both actuators, just because you're having trouble with both. Did the drivers side work right after your mechanic put in the first actuator? Duel zone take a different part number actuators than a manual system. I found them on ebay for less than 1/2 of the parts store. You have to know what part numbers you need though. I used the dorman brand in my car and they work great. You can make sure they work right before you put it back together. Also make sure the door work easy before you install the actuator. The part number for a duel zone is 604-106, they have them on ebay starting at 35.00 up.

 

I pulled the fuse 27, and no luck still having same issue.

When the mechanic replaced the actuator, cold air blew out but did not react to temperature adjustment. He wanted to take to dealer to re-program BCM, but i told him i didn't want to go that route because based on the feedback i got here the HVAC issues have nothing to do with the BCM.

So the dash is apart and still have same issues. Re-indexed passenger side actuator, everything works properly except when full hot it the blend door doesnt close all the way leaving luke warm air. Any thoughts? I'm thinking this needs to be adjusted some how..

I got a drivers side actuator today (doorman) but am still having same issues. When i clear the codes i took a look at the movement of the actuator *** on drivers side. It automatically cycles from full hot and then back down to full cold but when its finished resetting (or whatever it does when you clear the codes) i can't get it to react to the temperature change when i turn the ****. I can see that it is trying to react to the temperature change i adjust to but its like the **** is being held up by something. Its almost like the DIC reset goes too far to the cold side and then its out of its intended range to cycle back and forth when temperature is adjusted. This happens with the BRAND NEW actuator (and my recently replaced one) so i don't think its the actuator but i have no idea what it could be. This attempted fix is slowly turning into a nightmare....

 

I checked the part number on the drivers side actuators i have, both are 604-111 instead of the one you mentioned which is 604-106. Maybe this is my problem??

 

Those part numbers are not even close to what I have in my parts reference info.

No real life experience with the actuators but here is a link that might help.

http://www.digitalcorvettes.com/foru...d.php?t=135883

Hope your issue is not the HVAC control unit.

 

Are yours aftermarket or original GM? The ones I'm referring to are aftermarket.

 

According to what I find they are not the right ones. I went to ebay typed in your number. they are for much later vehicles and say they are not compatable to a 99 corvette. Go to O'Reillys web site and put the info in you will come up with the number I gave you. That's what I put in my car and it works perfect.

What part number was on your original? 15-72971

 

My numbers are GM and also give the AC Delco number. I always start with the manufacturer number. The correct P/N should have been on your original ones.

 

I'll have to take a look when I get back to my garage this evening, but it doesn't look like the one I had originally fits my 02 C5.

I should receive the new one I ordered tonight-Doorman part #604-106 GM part #52402588. Are there any things I need to do before the install? (Disconnect battery, disconnect fuses, etc?).

 

I'm still learning, but I think I've learned enough to know if your messing with anything electrical on your car you should disconnect the battery. I know it has to be hooked up to test things, but if your removing/replacing...It's pretty cheap insurance in case you touch something, somewhere to make it short out...you might just pop a fuse or you might fry something. These cars have enough electrical issues without creating any yourself. Maybe I'm just being a little over cautious?

 

I didn't disconnect my battery, I didn't even pull the fuses to reset the actuator. It went thru the calibrate when I turned the key on. Wait till it goes thru the reset before you try and reset the temp. Did you get both?

 

Ok sounds good. Thanks for the advice. I have so much apart right now, its probably a good idea to disconnect just in case .

I only got the one for the drivers side, just in case this one doesn't work or if the issue isn't the actuators and something else. I'll be working on it tonight so I'll be sure to report back what happens.

 

Then leave the other actuator unplugged so it don't send the wrong signal back to the controller. at least you may only have codes for the passenger side.

 

Well i can finally report SUCCESS!

I installed the drivers side actuator i ordered (Doorman part# 604-106), tested it out and the drivers side blend doors are now working. I am able to cycle between hot and cold as normal when i adjust the temperature.

The passengers side blend door was still not moving to full hot position after i had adjusted the big white gear inside the actuator (this was done when i first took apart the dash). I did not replace the passenger actuator since i saw it was still working, and the gears looked fine and not damaged. It seemed like it just wasn't set correctly when i initially adjusted it. So I took the passenger side actuator out again and set it aside. I then moved the temp door shaft (the white-ish colored piece that the actuator connects to) with my fingers to the full hot position. I then adjusted the actuator gears so it would slip right onto the white temp door shaft at the full hot position. I re-installed it in this position and success! It now goes to full hot and cold when i adjust the temperature.

I put the dash back together with no problems and when i run the DIC, no HVAC codes appear. Thanks so much for everyones help on here. I saved hundreds of dollars and learned a lot in the process!

 

whaat....do I smell the sweetness of success? Awesome job!
Thank you for posting your final outcome, enjoy that cold air and have fun!

 

Makes a big difference when using the correct part. So you left one in with the non correct part number? Sure hope you don't have to remove the dash pad again. Good luck.