That's the heater valve. It turns off coolant flow to the heater core when the dash temperature **** is all the way over to the cool side and the selector switch is on A/C.

 

Thank you. I'm trying to search for the part via various auto parts stores online and I couldn't find it anywhere.

 

I'm sure it's going to be a junkyard or dealer item.

 

Oh how right your are!

 

It's a curse that I've had to learn to live with.

 

Water Valve per 1997 Dodge Factory Service Manual. Dodge uses them to cut off the coolant from circulating through the heater core when the AC system is on Max output.

EDIT: Did not see that this had already been answered on the next page.

 

For this item I would rather get it from the dealer than a salvage yard.

 

I definitely agree... I can't imagine that it's that expensive a part. Incidentally it was the vacuum connection on this valve that I had accidentally disconnected a while back and then was in full panic mode for a few days when I couldn't get air from anywhere but the defroster and floor vents LOL.

 

OK let me bother you all for another thing. I am in the process of working on this thing and I decided to check all the vacuum lines. There is a vacuum line that goes into the engine (passenger side) via an elbow connector and there is a one-way check valve right there, then another elbow then a connection that splits into two different lines. Anyway, I took both elbows off the check valve in order to check it's operation but didn't really pay attention to how i took it off. Sooooo, my question is I assumed based on how these things work that the valve should be inserted so that air can be pulled away from the engine (i.e. the end that you can blow into, but not out of is facing the engine)... is that correct?

 

Air should be able to flow through the check valve towards the engine.