Hey, I'm new to this particular forum, although I'm pretty frequent on the OBS PSD forum. My step-dad has a 97 F350 with the 460 in it. Mine's a 95 with the PSD, so I'm fairly familiar with the trucks, but not 100%. To say it lightly, he's not much of a mechanic, so maintenance isn't much of his thing.

A few weeks back, his truck wasn't starting very well and he wanted a new positive battery cable. I told him we should do both because the neg was pretty bad too... he didn't want to spend the money, its his truck, so whatever. I installed the new positive and everything was fine, until now. His truck won't start, he says there's smoke coming from the hood, and he asks me to look at it for him. So I go to look at it, try to start it, and you can hear the starter engage, but it won't turn the motor. It just hits the flywheel. I had him try while I looked, and you can see the smaller wire that goes to one of the bigger terminals on the starter relay is actually jumping when he hits the ignition, and all the rubber on it is melting and burning. I tried jumping the relay with a screwdriver with the same, wire jumping results. Of course, I pulled the dipstick, and the motor is bone-dry, save for some 'sludge' that I get on the very edge of the dipstick that is akin to rusty pudding.

I'm hoping the motor isn't seized, but besides that, what could cause this problem? That, or could having a seized motor cause the wiring to overheat if, say, someone were to hold the ignition on without the starter being able to spin?

 

Well, if the motor isn't seized, you're probably very lucky.

Tell your step dad to replace the negative battery cable. Clean the connections very well on both positive and negative battery cables at all points.

I would also replace the starter relay. It sounds like it could be fried.

That's the best I can tell you- I'm sure others will have more to offer.

Oh, besides to add some oil to it. And it would be a good idea to get an oil additive too.

 

Agreed with above, clean all battery and starter connections, and replace that melted wire.

Before I did that though, I'd put a socket and breaker bar on the crank pulley and try to turn it over by hand, just to make sure it's not seized.

 

from underneath get a 1/2" x 18" breaker bar with correct socket to fit bolt on crank and try to turn over motor. If it moves motor is not siezed... if you can't turn it or it VERY hard to turn motor siezed or hurt bad and you will continue to fry wiring and starters.... if you can turn it just a bad starter, wires, solenoid...

 

If it's seized that starter will try and draw upwards of 800A trying to turn it over.
It's no wonder the insulation is melting off.