I am new to Dodge trucks and could use some of y'alls knowledge to help me make an educated decision on my present dilemna. Long before I aquired my truck someone removed much of the heater hose from the engine bay ( probably to put on another vehicle). My question is, There is a vaccuum operated device of some kind on a piece of the remaining hose. what is this and can I hook up the heater with out it? I bought a Chiltons manual but the device does not appear to be mentioned in the chapter reguarding the heater. Ypur imput would be much appreciated. Thanks

Can you post a pic of the offending item? There's nothing between the water pump/manifold and my heater core on my 86.

I got one of those valves on my truck. an 83 D-150 and I think it takes a small vaccum hose coming from inside the cab. this is a grey hose. the black hose from the cab goes to the manifold vaccum tree.

I have one on my 88 d150 also, it's called a diverter valve.

i discovered i also have one on mine... it looks to me like a small vaccuum hose goes to the cab and controls the flow of hot coolant into the heater. it goes on the inlet hose to the heater in the cab. or if your looking at the engine the hose on the left.

Mine has one too, but have no idea what it's for. Never seen anything in Haynes or Chilton's about it that I can recall...