Car= 1995 Pontiac Bonneville SSEi ELectronic Climate control.... The Heater has good air flow at max fan speeds. The heat is only cool/warmish after warming up the car to 200. The thing is it worked yesterday perfectly fine got wicked hott quick it was great.... Now today it totally sucks. If there are any steps i can go about to determine the problem myself that would be great. The temperature doesn;t blink like it useto as of today.Whatdoes it mena when it blinks anyways? How much does a heater core go for approx??? Any and all advice/help is appreciated thanks....

Too bad it'* newer than a 93. 93 was the last year you could pull your codes from the ECC (electronic climate control) without having to go to the dealer. The blinking display is telling you there'* a fault in the system. By your description, it sounds like the airmix actuator. It'* a door that mixes cold air with the hot to achieve the right temps.


The door might be broken. Randman has a good pic of where it'* located. If your dash (entire dash) were removed, you'd see it to the left of the glovebox. You might want to remove the passenger footwell hushpanel and look up there for anthing broken or disconnected.

well it doesn't blink anymore.... Maybe the blinking was tryign to tell me it was dying heh? but you set it to 90F and full fan and the display stays strong but u get like warmish air not even warm more cold then warm.... If it is this air mixture part is that costly ??? Would one from a junk yard be sufficent?

Ahhh....here you go:



Yours sounds like something is flopping around uncontrolled. Not sure if it needs to be replaced just yet. This pic is Randman1'*, he'* one of our gearheads. Might wait a bit for some others to chime in, as I've never had to deal with an airmix door personally. Lucky, I guess.

Or is it because I got the best year?

Possibly your heater core needs to have some acid (forget the exact name for it) run through it. I kinda am leaning against that for now because you said it worked fine yesterday.
I'm going to guess you have a problem with the CC control unit, just as Will suggested.

If your heater was "blowin' wicked hot" yesterday and not today, the good news is that it is not likely a bad heater core. The bad news is that it might be the airmix actuator. This airmix door thing is pretty tough to get at. See this thread: http://www.bonnevilleclub.com/forum/...360&highlight=

Maybe Randman has a better way than I did on my '97. I had to unbolt the whole dang dash to get at it. I think that you might be able to get to it by removing the glovebox, and the passenger airbag assembly and going down, but I was chicken to fuss with the airbag and did it the hard way. I would study it to learn an easier way if I have to do it again.

Before you start this job, check your heater hoses to make sure both of them are reasonably warm. If they are both warm and you can get no heat into the car, then some ducting problem is indicated. You may be able to tell if the airmix actuator is working by having someone punch in max heat then max cool while you slither your hand up where the actuator sits. If I remember right, it takes about 20 seconds for the actuator to react to the signal from the controller. You might try a flashlight and an extendable mechanic'* mirror to let you watch the actuator to see if it is working. (Shining a light on the mirror lights up what you want to look at) The actuator should push a lever that opens and closes the flap in front of your heater core allowing warm air to pass through into your ducts. I suppose the lever could have come undone, too. But, even that is still pretty tough to get at.

Due to the difficulty of replacing the air mix door actuator, I'd recommend having the ECC codes read at a dealer before removing the dash. As willwren stated, there are no on-board diagnostics for ECC after 93. For ha-ha'*, check the EXT TEMP display when the air is not warm. Mine read 168* and would only blow hot air if it was set to 90*. On the next setp down (85*) it was cool air. A faulty ambient temp sensor displaying an incorrect temp will not cause the temp display to flash.

If you remove the inner black part of the glovebox, you can at least see the ait mix door lever and actuator rod. You;ll need a flashlight cause it'* behind a steel dash support and plastic duct work. Set the temp to 60* and you should see the lever (white thing to the left of the red circle in the pic above) move to the left. Change the setting to 90* and you should see it move to the right. the totla travel is close to a 90 degree swing. Make note of any pausing during the travel as this would indicate the gears slipping in the actuator.

Note: the left and right swing may be different on a 96. The idea is to see the full travel of the lever when changing from full hot to full cold or vice versa.

The actuator is about $70 from the dealer and I would not buy a used one. If it comes down to having to replace it, you wouldn't want to go through the dash removal process twice. I should mention that there was a member on www.automotiveforums.com that supposedly changed the air mix door actuator without removing the dash. He gave instructions on removing the ECM, HVAC programmer and the heater core cover to get at it. Still to this day I have no idea how the connecting rod can be installed and adjusted using this procedure.