I hope I can find some info about this problem, because I've checked everything and I'm out of ideas. Recently, I changed the radiator and coolant temp sensor, then I replaced the A/C compressor. Since then, when I start the car, the temperature display flashes for a while, and when I turn the heat temp up to 90 degrees, all I get out of the vents is lukewarm air. Both the heater hoses going into the heater core are hot when the car is fully warmed up, and the coolant level is full. I bled the air out of the system with the bleeder on the thermostat housing, and the coolant seems to be totally full. The blower and the function of the climate controls seem to be working fine otherwise. If anyone has any ideas on what to check next, it would be greatly appreciated! Thanks

The flashing temp display on the Climate Control typically indicates a code is set in the climate contol system. I believe there is a procedure to pull codes out using a key combination, but given the symptoms, I would suggest checking the airmix actuator to ensure it is moving. The actuator has plastic gears inside of it that like to crack and stop it from moving.

A search for Airmix actuator should give you quite a few hits, and most 92-99 Bonnevilles are the same in this regard. There are also many solutions ranging from manual operation of the door to actually servicing/replacing the unit.

Hi Randall, Thanks for your reply, I really appreciate your help.. Can you tell me if I need to remove the entire dash to fix this actuator? Can I create an access door through the glovebox or underneath? I don't know exactly where it is situated in the ductwork, I'm assuming it is near the heater core, but I don't have a clue. I'd like to replace the actuator but if a manual operation is feasable, I'd try that tool. After all, the car is 19 yrs old, but I'd like to get 2-3 more years out of it. Thanks a ton!!

This is about the best thread I can come up with on short notice on this:
https://www.gmforum.com/1992-1999-91...n-pics-274213/

In my PA, I can pull the glovebox out and it is staring me in the face, on the left side of the glovebox area, on the top of the duct work. Lucky me

There is a pic in that thread however that shows guys working on it, but you can't see anything. It'* about in the area between the end of the HVAC controller and the left side of the glovebox.

Hi Randall, Thanks again for all your help, at least now I have some idea as to what I'm looking for and where it would be located. I may try to have the code/codes pulled just to make sure before I dive into it, but I'm 99% sure this is what is going on. The links you sent were totally useful and helpful! I appreciate your help with this one! Johnny

i have a 99 Bonneville SLE and recently, after disconnected the battery, the climate control module started flashing the temperature. even after 50 cycles it continues to do this.

I know the actuator works because the heat will be ON once started and after a few seconds it will blend to full cold. so when i restart the car it will reset to HOT. i even saw the arm move too. so when im driving the temp will stay cold and thats fine in the summer but now I need it to be hot. sometimes after driving i will play with the controls and it will magically randomly go from cold to hot, hallelujah! but and turning off the car and back on resets it all over and sometimes the blower stops working.

so the temp still blinks and i will temporary get the Hot air no matter what temp I set it to, then it will turn full cold and stay until i play with the buttons and bang on it and randomly "fix" actually it goes to full hot, still no matter what temp it is as long as its above 75 i think...

please help! what is the problem? do i need a tech tool to diagnose? what can it be? low/high freon? some short or bad resistor capacitor transitor... idk, anybody?