1997 nissan pickup

does anyone have the diagram of the heater hoses coming from the engine to the heater core. 1997 nissan plckup xe 2.4 liter engine.

The factory service manual does not have a diagram for the heater hoses in either the HVAC system section or the lub/cooling section. I went out to the truck to see, boy the difficulty enhancement engineers really worked hard on this system.

The hose coming off the top heater core port goes to a metal pipe at the back underside of the throttle body. This pipe runs under the throttle body and to the water pump. A short rubber hose connects this pipe to the water pump.

The hose from the bottom port goes behind the engine and disappears. I would have to remove the EGR and rear engine lift bracket to see where it goes. I did not see where the heater control valve is located but I suspect that it is under the throttle body somewhere, but it could be behind the engine or even under the dash.

Its funny that the heater/ac chapter in the FSM only cover the AC. The only reference tot he heater is in the chapter title and in one schematic of the system.

@Keith; I like that one “difficulty enhancement engineers”!!!


It’s strange how FSM’s – which are supposed to have the final say on the specs for the car and all its parts --these manuals surprisingly are missing key info sometimes. For my early 90’s Corolla, the FSM fails to specify what the temp vs resistance curve is for the ECM’s engine coolant temp sensor. I had to look that info up in an aftermarket Chilton’s manual in order to test that part.