How to turn your heater core off and on in the cab.

[Waterloo]

I finally got to drive the truck, and this new ball valve is working like a champ! I had heat in the morning and ice cold AC that afternoon. Flip dash switch up and hold for 3 seconds, return to off position, AC starts blowing. Want heat, flip switch down for 3 seconds and then return to off position, heat starts working. Only used it a couple of times, but the darn thing works. And I did add an in line fuse, 2 amp.