I have a 1986 F250 that ran great until yesterday. While driving it it started missing and then completely died. When I popped the hood I noticed a burnt wire that goes into an 8 block pin connector. The wires that are part of the problem is a red with lt green stripe and a yellow that goes into one section of the connector and connects to a red and red with lt grreen stripe on the engine wiring harness side.Previously someone bypassed the connector and connected the yellow and red with green stripe to the red and red with green stripe with a fuseable link. A sloppy job but had no problems previously. I don't know much about the diesel engine electrics but I'm thinking of some component failure, maybe glow plug controller. injection pump shutoff solenoid?

If anyone can point me in the right direction it would be appreciated. Also any advice on upgrading this system and the necessary parts required

 

When you turn the key to "on" you should hear a "click", that's the IP solenoid. If you don't hear the click, try connecting the IP solenoid directly to 12v+ via jumper wire. I use "alligator clamps" from the + on passenger side battery to spade on solenoid. The spade that you want to connect to is the one closest to the radiator.
Try to start the truck BUT YOU'LL HAVE TO DISSCONNECT THE JUMPER WIRE TO KILL THE ENGINE. Please don't forget that part.
If that doesn't work then you've likely smoked the fusable link in the bundle of wires next to the voltage regulator...if that's the case post back...more work and diagnostics needed.

 

I had a look under the hood today and after some research that the system was upgraded and a very sloppy job to say the least. There was a lot of potential for shorts as well. I found a pre powerstroke engine harness locally and found the schematics on dieselmans page, so when the new controller comes and I install everything I'll post an update. Even though the wiring was a hack job,the fuseable link on the main harness side saved it from doing further damage. Also thanks for the info regarding the solenoid test. If all goes well the next step is to clean up all the wiring in the engine compartment.