Turn the key ON not to start and this fuse(#24) under the hood blows. I have disconnected wire harness going to the PCM module , the harness goingto the interior cab at the firewall. Still the fuse blows. I unhooked all the engine sensors,tps,cts,crank,maf,coil. Still the fuse blows. Does anyone have an idea?????

 

Check the upstream O2 sensors. Sometimes the wiring rests on the exhaust and burns through, causing a short to ground.

 

See this thread and it references: https://www.f150online.com/forums/sh...d.php?t=247760

Steve

 

I found the wire harness burned or melted the wires on the Right(Passenger)side just on top of EGR pipe. Repaired wires and re-routed the harness and the fuse not blowing and truck running. Thanks for help

 

Great feedback.

Glad you got it fixed.

Steve