will not start when hot

[Bandit76]

the other thing that I did with mine is wire a momentary pushbutton up to the starter. This eliminates the whole starting circuits. Like a hot wire. You need to disconnect the main start wire and run two new wires from your starter to the cab or temporary somewhere easy. This way you know that there is nothing else stopping the circuit from being made. Just make sure the key is switched to on so the ECM and all other power is everywhere. It will crank with the key off just so you know. I did this to mine and was going to dig up the starting issue. Mine was the exact same. I did this and it started first time every time. I was actually planning on permanently rewiring a disabler and start circuit with it so that thiefs could wreck my ignition switch trying to steal it and not be able to figure it out. That actually happened once. Ignition switch wrecked, window smashed, steering wheel freewheeling and my truck sitting where I had left it.

Dimming lights to me means that it has found another path to ground and is by passing the entire circuit somehwere or The heat soaked starter is also a very good possibility and yer pretty much stuck replacing it or smacking it with a hammer periodically. Locked rotors of any motor will draw a ton of amps and go no place.

Aside from getting out a voltmeter and seeing if you have voltage at the terminals while it is hot is about the only thing left. You could take a ring terminal and hang it off the starter terminal that cranks the starter. Put the wire to an area in the engine compartment and tape it off so it can't short on anything. When this happens again, take the wire and connect one end to a 12 volt tester and connect the other lead of the tester to the frame somewhere. Get someone to crank the key over and see if your tester lights up. If it does, then you have power and the circuit is fine. If no light, then you pretty much can count on getting a new starter.

Wreckers are good places to go if you can't afford new. No matter what spend the $12 and get a new solenoid for the new starter because ripping your starter out over and over is a pain

Oh yeah, if you're tester light doesn't light up, then work your way backwards through the whole start circuit. Fusible links, ignition switch, firewall connector and check for power at these spots. I always start in the middle of a circuit somewhere and work my way in the direction of results. No power here, then go back further.Etc.

If you can find an older HAynes book, the schematics are way better. The new ones are now simplified block diagrams and awful in comparison.