[2008 Armada] Heat issues
I just purchased a 2008 Armada SE and am having issues with the heat cutting out now and then. The first time it seemed to fix itself. When I brought it in for service three days later they said it was working fine. Now it has happened again. I found a few threads on here surrounding this issue and did some self diagnosis. I removed the HCV cover and removed the worm gears (which appear fine). I turned the valve counter clockwise which got the heat going. I replaced the gears (with the valve in the open position), but as soon as I started it the valve closed and cold air again. Because the valve closed I assume it's getting power? I then removed the gears, opened the valve and replaced the cover (without the gears) and it seems to be working for now. It's in the 30's so I only need heat now. What is my next step? What would keep the valve from opening? Any help greatly appreciated!