[my240]

I'll get after it again tomorrow. This is great information. I'm pretty sure wiring is original because my father in law bought new. More confused than frustrated at this point. This J-Stud thing is a question. I'll trace wire from alt. to see if I can locate it. They all seemed to end at the fuse box block and that looks like a lot of fun,,,but we'll see. I'm more mechanical than electrical at troubleshooting. Let me add a couple more questions. When the truck starts voltage gauge is running pretty high inside cab. Second what makes it shutdown. Does a wire get so hot it temporarily melts or something, the comes back as it cools off? I'm not understanding from one day to the next it starts and runs fine then next day nothing. And it's just sitting in garage. Thanks for all ideas and answers.

Just got back from garage. Battery after trickle charge is 12.8,,,12.8 at alt,,, Truck started right up. No blower fan running at all today? Looked on firewall for this J-Stud. Nothing. Is it down behind the distributor. Something there but would have to remove distributor to get to it. By pics I could find it should be beside brake booster? Will hit it later.
Thanks again