Power wire from starter

[possum70]

I have a 1978 blazer. This morning I go to start it to run bus. Nothing. No clicking or anything. Try to jump it... nope. Check inside. No lights, horn, radio or aux lights. But I do have my ham radio working and it's wired straight to battery. Now on my starter I pull the main wire from battery and I get sparks and the starter stars running non-stop. Key is off and starter is whirring. I unplug the battery to stop it. My battery cable, in PO life, I'm guessing, had arced and welded itself to the solenoid. It wasn't bolted anywhere and was stuck to the solenoid. And when I pulled it it must have jumped to another post, "R" maybe? Now that I have it wired back up properly I have nothing. If I jump a wire from the main battery post to the "S" post with the ignition wire it will crank. My guess is now I have no power going to the truck from the starter solenoid. The problem I am having is tracking that one wire to the fuse box, or wherever it goes.
I'm not good at following schematics and all my wires seem to be black ones, unless I wipe them off but then I only get a faded semblance of a color. Does anyone have a picture of where that wire goes into the junction box or whatever the back of the fusebox is called that sticks through the firewall into the engine compartment? If that is indeed where it goes. I would even settle for a good description.

thank you
possum

 

[diesel4me]

The wire that activates the starter when you turn the key to start,is a thick purple wire,that goes to the "S" terminal on the solenoid..it comes from the fuse box,goes to the neutral safety switch (which might be the problem,if it was not in park or neutral or the switch went out of adjustment)--also I'd check the two fuse links on the thick red wires at the starter solenoid that attach where the positive cable does,see if they look roasted or not..sometimes they are,but still look OK..I think there is another fuse link near the power brake booster too--if any of them fry,it wont get power to the fuse box or all of the wiring ,some things inside might work,and others wont..

The fact you can get it to crank by jumping the solenoid proves its wiring troubles,not the battery ..might be the ignition switch,but they usually wont die suddenly like that..