Fuse 24 blows when starting

[Mark 1]

Up towards the top of your drawing, right underneath the ignition switch. Is there a line splitting off that says it goes to engine controls?

If so, that goes to the PCM. It is possible that we are seeing the effects of bad capacitors in the PCM. Everything else in that circuit is pretty robust and doesn't usually succumb to heat exhaustion.

The diagram in the Haynes manual shows: ignition switch - fuse 24 - Starter interrupt relay - clutch position switch - starter relay - starter solenoid. I don't see any other connections. I also checked the PCM diagram to see if the same wire color code (Red/lt. Blue) showed up there and it did not. Thanks for the suggestion.

 

[Curious Hound]

The diagram in the Haynes manual shows: ignition switch - fuse 24 - Starter interrupt relay - clutch position switch - starter relay - starter solenoid. I don't see any other connections. I also checked the PCM diagram to see if the same wire color code (Red/lt. Blue) showed up there and it did not. Thanks for the suggestion.

Thank you. I don't have drawings that new for a Ranger. I was using my 1993 drawings, plus 1997 F250 drawings and figured that should be close. The starter interrupt should be the security function.

 

[Mark 1]

Following up on this. With the help of my son, the problem is solved.

The Fuel pressure sensor circuit also uses fuse 24 but is not shown on the starting circuit diagram. In the engine compartment, there was a bundle of wires that were just touching the exhaust manifold. We moved and covered the wires with electrical tape and the fuse stopped blowing when trying to start the engine when it was hot. Thanks to everyone who helped me figure this out.