Right on Bartamos- Thanks. My unit looks a bit different, but still the same simple Simon type. The sheet metal diverter portion says "Harrison". The heater hasn't ben installed on the truck since long before I owned it. I just had the leaking core restored. I was thrilled when I looked up under the dash and saw the flexible pipes leading to the defrost vents tucked up there. The one thing I'm not certain about is if there should be some kind of valve in the set up to stop the continuous flow of liquid though the heater core. Right now the two heater hoses are joined together with a hose barb under the hood. It looks like they just connect up to the naked copper end pipes of the heater core that will be poking through the fire wall. The heating "module" on the dash is a single button that seems like it will be the on off for the fan connected to the heater core box. I'm thinking the heat will simple radiate into the passenger compartment non stop with out some kind of physical disconnect valve to stop the water circulation.
