I'm not sure that I want to try taking it off at this point, since I'm not sure what I would be looking for when I did. But if I understand you correctly, even if the cable is moving, it may still not be opening and closing the valve properly?
Supposing I did remove the valve, would I be able to see the problem clearly on the back side of the valve? In other words, if the cable is either not connected to the valve properly, or is positioned such that it is not opening and closing completely, will I be able to determine that?
Also, how much coolant are we talking about that will spill onto the floor? Should I drain the whole system before proceeding, or is this a small amount that I can catch in a bucket?

 

Bought the replacement from Europartshouse. Got it in this morning. Learning experience but it's done and seems to work.

 

Hello All,
I'm replying here so the old history is available.
The heater valve that I installed a few years back stopped closing. It looks like the wire is still attached to the control and the control works moving from cold to hot. But hot to cold does not move the valve. I can manually close the valve. In other words, the valve is connected to the control but only moves in one direction.
When the control "broke" I could feel it. It felt like something (a spring?) had come loose suddenly.
I'm looking at it now and may get it fixed soon, but I thought I would check here if anyone has any advice.
Thanks.
Todd

 

I found the problem. The rubber housing for the cable running from the control to the heater valve broke so the wire does not move inside the housing properly. I don't know if I'm describing the parts right, but it is pretty clear to me now.
I think I will need to replace the cable.

 

Thanks. I was able to get this fixed some time ago. There were two problems. The earlier problem was the heater valve, as you mentioned. The later problem was the cable coming loose from the manual control. I went in under the dashboard and was able to get it reconnected.