83 944 heater

[TCGVUS]

When heater lever to far right-plenty of heat but when returning lever to off position far left heat still flows from vents. To shut off I must go under the hood & shove metal lever toward firewall & then heat stays off. This lever located about middle near firewall with metal rod connected to pull lever back & forth. My question: Is this metal rod attached to the lever mechanically on the HVAC control lever on the inside of the car. If so & it is not attached how to fix? No vac hoses or electric motors involved, right??

Thanks!

[pfarah]

You are correct. There is a control cable running from the heater valve to whats called the ventilation switch, which contain three levers that control air direction and heat amount. the two top levers control airflow direction into the cabin. The cable you need to inspect goes to the third lever (bottom) that controls the heater valve. Check to see if the metal securing clip is missing, or if the cable securing tab on the vent switch is broken.

Cable securing tab locations:


Airflow direction levers:


Cold/heat lever:


Metal securing tab:

[jjeffries]

TCGVUS: Welcome!

I think you're looking at the heater valve, behind cylinder head, which either allows hot coolant to flow thru the heater core within the dash's HVAC system, or keeps it circulating just within the engine and radiator.

When you slide the cabin control it's actuating a standard Bowden cable, which is what pokes thru the firewall to the heater valve. If you have someone inside the car wiggle the slider while you look at the heater valve in the engine bay, you'll see what's going on. Unlikely that the cable is bad.

More likely, your heater valve has failed internally; they are made of plastic and not particularly robust. A new one is ca. $20. BUT, if you want to changes the hoses associated with the heater valve, you'll be dash removal mode ... which is where I'm presently at. See my thread around page 14. I have the heater unit on my workbench, including the controls, if you'd like any photos.

Kind regards, John

NB: Patrick beat me to it ... excellent pics.

[curtisr]

Let me add this: the Bowden cable terminates at the heater control valve located near the firewall by the reference/speed sensor cable connections. Sometimes the valves fail and you're stuck with having the heat on. If you don't plan to use your car in the winter months (think cold climates) then you can disconnect the cable and move the arm to which it was attached towards the passenger side of the car and see if your results improve. If they don't, it's time for a new heater control valve.