I have done a search and found a lot of information. I need to replace my air mix and have a question. First vehicle is 1996 Pontiac SE with auto temperature control. My glove box door has two air vents. Behind the glove box is a plenum that makes removing the screw retaining the heater core cover all but impossible. To remove the plenum looks like dash removal is required. Help, I don't see any mention of removeing the plenum. Do they all not have the plenum?
Paul

You have RPO code H4U on your spare tire cover, designating the SLE package. That'* the only way you got Auto controls.

Yes, you can change it without plenum or dash removal but it'* TIGHT in there. Remove the HVAC controler (red connector) and you can reach up to the airmix with very short tools. Remove the glovebox for visibility.

Thanks for the reply. You are correct label on spare tire cover list H4U. I was going by the original sticker when vehicle was purchased saying SE. O well the question: I am following instructions posted at trialsnuts.com/ecc.pdf and to replace air mix actuator the two screws holding heater core cover need to be removed. I can see the upper screw between duct and the frame that has the hole where you see air mix lever. It looks very difficult to remove that screw. Are you saying the air mix actuator can be replaced with out removing heater core cover? Sure hope so. Yes, glove box has been removed.
Thanks again,
Paul

I think you're calling the programmer the cover.

Yes, you have to remove the programmer. 2 screws. Lower screw will be a bitch. That gives you a vertical 'channel' to shove your arm up from underneath.

The programmer is black with a large red electrical connector. Also has vacuum lines going to it.

Again thanks. I know what the HVAC programmer is. It is under the dash with 5 vacuum lines going to it. I'm talking about the heater core cover as listed in step38 of instruction at trialsnuts.com/ecc.pdf. The heater core upper screw can be seen through glove box opening between air bag brace and duct.
While i have you, got any place i can order new air mix actuator on line with out paying GM retail. Being retired I look for deals. LOL
Paul
PS: This job would have been a lot easier forty years ago. Under dash work isn't what it use to be.

No, the core cover doesn't have to come off. But you may have a problem with the length of the airmix actuator harness. Plan on using the old harness to lengthen the new one to make this procedure easier for reassembly.

Retract and recline the seat fully. You may find it easier to recline upside down underneath to do this. I alternate between that and kneeling in the open door.

There'* another electrical connector above one of the two actuator screws (farthest to the passenger side) that you'll have to blindly remove to gain enough clearance for a short screwdriver bit.

This works very well up in there:

http://www.sears.com/shc/*/p_10153_12605_00943401000P?

3-piece finger grip socket adapter from Sears.

You can buy the actuator from GMpartsdirect for about $58
The part number for a (95) is #16141822
I don't know the number for a (96) or if it'* the same.
You can ask customer service at GMpartsdirect.com

www.rockauto.com

Use the discount code in General Chat.

It is true that you don't need to completely remove the heater core cover, but you may find that it will be a lot easier to access the screws on the airmix actuator if you pull the cover loose. It'* all about being able to get yer hand up in there.