Posted by Willy-N on Wednesday, August 27, 2003 at 11:08AM :
In Reply to: Engine Picture Question - Let's try this again posted by Cliff on Wednesday, August 27, 2003 at 10:34AM :
That is to shut off the flow of hot water to the heater core inside the Cab. It will keep your cab cooler in the summer with it closed. Mark H.
Follow Ups: