starter engaged while driving, then wouldnt start

[aviator18]

My buddy has a 4.3 in their truck (88 GMC Sierra) and they were drivin it yesterday and she started squealing and grinding like a mofo, so we troubleshooted it down to the starter (starter was super hot to the touch) and we popped the hood and you could see smoke emitting from around where the starter was,and smell it hardcore.

Turns out that the starter was engaging when it was driving, causing the grinding, we determined that the solenoid was gone,

so we changed out the starter, no problem, go to fire it up, and nothing, more smoke and smell is stronger then before. So we pulled the starter again, this time the small wire that normally connects to the solenoid fell
off with it

My question is, where does the wire connect to, so i can replace it, second what would cause it to short out and smoke like that? and, isnt it just a ground? and if it is cant i just run it to the frame?

[horse482]

The small wire is the start wire, it is what sends the signal from the ignition switch to the starter. On the starter there are two small terminals and one big. The big lug is for the battery wire, the small lug marked "s" is for the start wire, the other small lug can be used as a switch. It is possible that if you hooked the start wire to the wrong lug it could burn the wire. Good Luck!