1976 cj-7 no power until starter is engaded

I have a 76 cj-7. I was driving it the other day and it shut off like i cut the key off. Now when i turn the key to the run position thing that gets power is the volt gauge, but when i turn the key to start and engage the starter everything comes on and it will fire up but as soon as i let off of the key and it returns to the run position it shuts off and everything except volt gauge loses power. I have replaced ign. Switch chkd all fuses chkd ign. Switch adjustment and replaced ign. Control module. On the module there is a plug with 4 wires in it and one wire that stands alone, the plug was fine but i traced the lone wire and it runs to the firewall large pass through plug and is cut off and goes to nothing, where is this wire supposed to go? It has obviously been this way for some time so i dont think this is the problem. Im going to chk plugs to ign. Switch tomorow because they did not look great ( white one looked a little burnt inside) just wondering if anyone has run into this issue before.