I can not seam to find the plug for the block heater on my 1997 e350 7.3l. I see the wire goes into a harness from the heater itself but where does it go from there? I do not see it up front

 

The cord comes off of the block heater right above the oil filterand runs down the top of the driver side frame rail. It doesn't go into a harness that I know of. The end with the plug on it should go through the core support somewhere between the radiator and driver side headlight.

 

what you're probably seeing as a harness is just a hard sleeve that the cord (and only the block heater cord, and nothing else) runs through along the top of the frame rail. its held in place with a few of those Christmas tree push pins. pull that sucker straight up and it'll come loose. then you can yank the rest of the cord out from wherever its hiding and re-route it to your preference.

the cord on my new truck was coiled up by the PO up near the hood latch and wire-tied. ...which should have been an obvious sign that it doesn't work! time to test to heater itself...

 

On my Van the PO decided to run it up to the top beside the Heater Box and have it come out between the Hood and the grill...When I replaced it (Twice now) , I ran it along the frame and across the bottom of the radiator and down below the bumper....

 

I have a 97 F350 and can't find the plug either. Is it possible my truck doesn't have the heater in the first place?