Hi Everyone, I have a 1980 Olds 98 Regency, 51K original miles. The heater has been stuck on in this car for the two years I've owned it. I have replaced the heater control valve, and traced the colored hard plastic vacuum lines to the control in the dash. I could use some suggestions. Is it the Tempmatic system? The hot & cold lever slides easily and moves a lever behind the glovebox. However, the bottom of this lever is attached to a vacuum pod of some sort with a rubber vacuum line that doesn't seem to work no matter what position the controls are in. I don't know what that part is or what it does. Thanks!

 

On my Regency's, I had to change the temp controller which is mounted on the heater box...take the glove box out and it is really easy to change. On another Regency, I plugged the vacuum line on the water valve on the manifold for the summer and then put the line on for heat in the fall...then I discovered that the temp controller was the problem.

 

Most Tempmatic failures I've had traced to the vacuum relay check valve- little diaphram looking thing on back side of the programmer. If the thing fails it will stick in either full hot or full cold.

Most GM dealers used to keep them on the shelf if that tells you anything.

Me Custom Cruiser wagon has had a vacuum line teed in to the VRCV for years. If I want heat I stick a golf tee in the open vacuum line, for summer it stays unplugged. It's in the glove box so I don't hear the hiss.

But yes, it can be easily accessed thru glove box if you want to repair it and can find the part. Last ones I bought were over $40 each and had been about $10 for years.