I have a 77 F250. The other day My Hired Man said the truck wouldnt start. WHen I opened the hood The Battery Cable shielding were melted on the post ends on the battery connectors. I replaced the battery cables and cable to the starter. Still No Crank.

I replaced the Battery and Solenoid on the passenger Fender. Still NO Crank!

I tried jumping the starter solenoid on passenger fender and nothing. So I replaced the starter. When I try to start with Key I get nothing. When I jumper the solenoid the starter will turn over the engine.

Last night I replaced the Ignition Switch. Everything looked good on the plug on the back side of the Ignition Switch. Still No Crank when using the ignition but I can get it to crank when I jumper the solenoid.

I am stuck now to what it could be. Please Help!

 

Check the ignition fuse

 

First and foremost, you have to figure out what caused the battery cables to melt. That's a LOT of current (dangerously high). You seem to have replaced or serviced most of the things in the path that would be suspect, so that may be a moot point by now.

Pull the RED with BLUE stripe wire off the 'S' post of the solenoid, and make sure that there is power at this wire (test light or multimeter) when a friend holds the key in START. Report your results.

No such "ignition fuse" on these trucks, whatever that is.

 

So I tested the Red/Blue Stiped wire when key is in Crank Position. i get a bright light signal on test light. Made me scratch my head as it is getting signal to start. So it has to be the Starter solenoid as it must have gotten ruined from the bad starter immediately. Went down to parts house this afternoon and Installed a New one. Guess what it works!

Thanks again for everyones help!