Hi guys I did a quick search but could not find any real info on the fuel heater that is on the top of the fuel filter. When is it powered up? What I want to know is if it is on all the time or is it controlled by the computer to only run at certain temperatures. I won't have a computer in the crew cab but would like to avoid gelled fuel if possible.
Thanks Grant

 

On the first generation engine, I believe there is an internal temperature switch that opens the circuit above a certain temperature. I do know the computer doesn' t control that circuit.

 

Is this switch inside the heater or does it use an existing switch on the engine?
Grant

 

It's gotta be an internal switch because the wire that feeds it is hot when the ignition is on. The manual says it kicks in between 43 and 53 degrees F. Man, it's nice having wiring diagrams.

 

Thanks again guys, I should be able to just wire 12 volts to it thru the ign switch and forget about it.
Grant

 

That's how the factory did it.