I'm starting to work on several issues my old '82 SEC has. Frist I'm looking into the climate control system. I have constant heat unless I roll the dial all the way up to get the AC to come on, and then it blows cold. I've checked the monovalve inside and all looks good; rubber is in fine shape with no cracks or deterioration, and the solenoid works the plunger. I did notice that the solenoid is active (plunger extended) no matter what setting the system is on. Is this correct? Are there any other rubber components within the monovalve body itself that I couldn't see?

My next stop in this diagnosis is resoldering/cleaning the control board. The blower works on high/low speeds, but not all the time in all switch settings. This seems like a needed thing to do on a 20+ year old car. What else can I look for if this doesn't take care of the problem?

Cliff