300sd Heater Wont Turn Off!!

ANY HELP WOULD BE GREAT THE HEATER IN MY 81 300 SD WILL NOT TURN OFF AND I DONT KNOW WHY THE AIR WAS WORKING FINE A FEW DAYS AGO AND NOW THE HEAT IS STUCK ON IT HAS EVEN WARPED THE DASH ITS SO HOT! PLEASE HELP I CANT EVEN DRIVE THE CAR NOW THANKS IN ADVANCE TO ANY REPLYS

[Gilly]

Mike:
We all kinda hate all capital letters here, call us kooks....

Sounds like the rubber bellows in the heater valve may be torn, there is a repair kit available. Disconnecting the wires from the valve won't stop the heat if the boot (bellows) is torn inside. Even if the boot were OK, disconnecting the wires would give full heat, this is the fail-safe mode.
The valve is back near the battery between the twin firewalls, has a 2 wire electrical connector and 4 screws holding the top on. Take out the 4 screws and pull the assembly out of the valve by the center part (the knob looking thing). You'll see a round rubber disc on the opposite end. Pull slightly on the rubber ring shaped thing on the end and look at the flexible rubber disc, if there is a rip or hole in the rubber disc, that's your problem.

Fee for all this advice? Shut off your cap lock!

Gilly

gillybenztech, thanks for you very much for your help sorry about the CAPS was a little over excited about fiding this website!!

[Gilly]

Just call me Gilly.
No problem, let me know how it's going.
You'll lose a little coolant when you open the valve up, not too much.

Gilly