"95 88 w/o electronic temp control. Does anyone know if the temp control is vaccum actuated or electric?. My temp control works some of the time, ie; turn it to cold and get cold, turn to hot and get hot air. Sometimes it will only allow hot air in. Have checked the air mix door and it is functioning well. The heat control portion is not available as a seperate part (have to buy the whole panel). I have no problem buying the whole unit if I have to. With the grief you hafta go thru to get to this thing, I am not a fan of a JY part and end up with the same problem.

If it is similar to the Bonnevilles, heat and cold are determined by the position of the airmix door which is electronically controlled for it'* position. You say the airmix door is finctioning well, but it is could appear totally fine until you experience the problem. You would want to watch it operate when the problem is occuring to confirm the door is operating properly.

Yeah, I figured it could be an intermittent problem with the air mix actuator. I am driving around now with the glovebox door off waiting for the problem to surface again. 'Course with it cool outside, everything is working fine!!! For the miminal cost of the actuator, I may just go ahead and replace it. At 167k, it could be a little tired and not wanting to work when the ambient temp rises. Since I am replaceing compressor/clutch, receiver-dryer and conderser, a $35 acutator is pretty small. Central Texas summers are and adventure in driving thru hell!!!!!

Sounds like a good plan. Within the air distribution system, heat and cold are really only a function of the position of the "blend" door position in the system. In this area, a faulty actuator is usually the culprit. Only other possible problems could be the HVAC programmer under the passneger side dash (we have had a couple fail here, but not many), the HVAC controller itself on the dash (again, we may have had a couple fail but not too often), or the blend door is binding (can't say that I can remember anyone actually having a binding door).

If the rest of the system is functional (A/C components, blower motor, etc.), then that leaves you with the actuator, the programmer, the controller or a binding blend door. I believe replacing the controller on an 88 is much easier than on the Bonneville, since on an 88, my understanding is that you have direct access to it behind the glove box, where a Bonneville unit needs to be accessed from underneath the dash.

Programmer? I do not have the electronic climate control so does that mean I don't have a programmer or should I start looking for it? The HVAC controls on the 88 are not to difficult to get to, the hard part is pulling all the trim off the dash toget to it. :?

Yeah, I know. Get a FSM!! I am looking hard and heavy for one.

Hmmm....I am pretty sure you still have a programmer, but maybe it is built into the HVAC controles on the dash. I'll need to look at my FSM'* to double check. Even if you do have a seperate programmer, I wouldn't jump to any conclusion yet, that it is faulty. We need to try the "cheaper" fixes first.

I just had the same problem with mine. I'll almost guarantee you its the actuator. Replace it with a new one, cause you're right, its too much work to do twice and this part is prone to failure on older cars, so a used one is probably not a good idea.