The Air Mix motor is what controls the H20 valve position. Try taking the cable off and moving it by hand to either position to see if you have hot air then.

 

It's on page 21-43 of my manual, might be a few pages off in yours, the title of the section is "Heater Valve Cable Adjustment". Have him turn the heat up in the car, you should see the cable open up the valve.

 

You beat me to it slows

 

Check that the heater valve cable is connected and working. Here is a picture of the heater valve. Mine will be a little different than yours because I have rotated it 90 degrees.

 

That valve is the one with the full range of motion. I've already tried taking off the cable and moving it by hand. Still nothing!!!!!!!!

What I haven't done is take it apart and see if it's really moving the valve inside the unit.

I know the heater isn't complicated. it just doesn't want to work for me.

 

Pull the outlet hose off the H20 valve and make sure the valve is open when you move the lever.

 

If that valve was not letting water in, wouldn't the water coming out be "warmish"?

 

If the valve was stuck closed, the outlet H20 hose It would be "kinda" or "quasi" warm, but not hot. I've seen the Lever's attachment to the ball valve on H20 valves break in the off position. The cable still move the lever, but the valve inside doesn't move.