OK - I had to reply after the great information supplied by this forum.

I have a 96 SLE SC and the climate control temperature started blinking after I replaced the battery. Pretty common result I read is that the actuator'* plastic gears break. I looked at the photos and write ups and determined that it is probably the actuator as the movement is not smooth and the compartment is cold and hot at times.

Anyway, after looking at what a nightmare it is to reach, I searched to determined if there was a better or at least easier way. After the glove box is removed, I used a solder iron to melt the plastic duct work out of the way and completely removed it. After it is removed the actuator is easier to access and remove. The duct work reinstalls and with duct tape, airflow is back to normal. The glove box covers the entire mess.

I just ordered the replacement part from GMPARTSDIRECT

The entire process took about an hour.

Thanks

I've done that on other cars in the past, but I find the 'long reach' method also only takes about an hour, and I don't have to melt anything.

Hmmmm...
How large of a hole did you need to make and exactly where in the box did you make it?
I'm for anything to keep me from standing on my head for an hour. I'm sure you could
find a better patch method than duct tape if you wanted a more finished appearance.

Got any pics?

I've been putting off this job because it'* winter and my actuator will only blow heat now. In the next month or two I will soon be frying and will be forced to fix this or rig it.

How do you know for sure that gears are broken?
I have exactly the same problem. After disconnecting battery my ECC blows only hot air,but it could be ECC "memory loss" as per factory service manual and needs only Tech 1 scan tool to recalibrate ECC.
I asked dealer how much he charges for that. Price is $108.
A little too much in my opinion.
Then again I'm not sure that recalibration will fix it and maybe gears are broken.


EDIT: By the way,
sle_sc ,what'* the part # for this actuator from GMPARTSDIRECT ?

The Part Number is 16141822

No Photos yet, but I melted the plastic in the left vent area behind the glove box. Fairly easy and just take your time. I worn mechanic gloves and placed my hand behind the vent so the solder iron would not poke thru to other components. Nothing ready behind the vent that will melt that fast anyway.

A 7/32 box wrench took the two holding screws out of the actuator mount. The vent went back in with the mounting screw on the right side and some duct take on the left side. Not pretty but functional and is covered by the glove box.

I read that the basic fix was laying on your back taking the seat out for a bit more room, taking out the Heater core cover, ECM, Power module, or the entire dash out -- arggggggggggggh too much!!!!

I usually fix items following the manuals for my classics, but as my daily driver I thought that this would be easier and there is not a visible sign once everything is re-installed

Just an easy fix suggestion.

Also, I special ordered this SE SLE in 1996 and it is 1 of 367 base Bonnevilles with the Supercharged engine per Pontiac.

I'm sure mine is the actuator. You can hear it trying to move the door.
It goes, errrrckk, errrrrck, errrrrck. Quiet noise behind the dash.
If I turn the temp up to 90 and down to 60 about 5 or 6 times I can get the car to
stop blowing hot all the time.
I feel confident its the common air mix actuator gear that is cracked.

I may just try this method of cutting the hole. My 95 is pretty much a beater at this point.
There is so many things wrong with it that it is way more than totalled even if I do all
the work myself. I need quick, cheap fixes at this point.

The actual procedure is laying on your back OR kneeling in the open door with ONLY the Programmer removed from the vehicle. Not the cover, not the PCM, or any of that other stuff.

It'* very simple. Had you asked for more specifics, we would have been happy to share them.

Thanks for part #.

Rockauto has it for $64.79.
I think I will try to inspect it closely, maybe even remove out of car before ordering .
Just don't wan't to end up spending $$ for something I don't need.
There are 7 diagnostic codes:
Temperature sensors inside/outside,
solar sensor,
E&C data line failure,
serial data line failure,
air mix door motor(circuit open or shorted)
and the last one is
Keep alive memory (KAM) lost: sets when battery is disconnected.

The other thing is after you install new actuator ECC must be calibrated(codes erased) in order to stop that blinking anyway.
In the end it'* allmost $200 question,what to do first.

That just depends on how much room you need, and is a personal thing. On the '93, the PCM and Programmer are right beside each other and by simply pulling the PCM out (only takes a couple minutes), you can increase your operating space. Loosening the heater core cover can help too. Removing the actuator is simple - having as much space as possible helps to get the replacement installed.

Inspection of the actuator is easy. Remove the glove box and watch the airmix door movement through the hole in the dash brace. If it moves erratically, the actuator is toast. Or, alternatively, if you can move the airmix door position with a screwdriver (through the hole), the actuator is toast. Don't go Hercules on the thing, but if you can move it with mild pressure the shaft is slipping on the gear.

Calibrating the system is almost as easy. Remove the actuator arm from the airmix door, set the temp at max to drive the actuator to the hot position, push the arm on the airmix door as far to the right as it will go (moves the airmix door to the max heat position), and reconnect the actuator arm.

Well, FSM says to clear codes with Tech1.
I guess it'* a part of calibration too,otherwise there would be no temperature display blinking.