mab2030

Good afternoon folks! I apologize for making my first post on this awesome site without an introduction; however I have been lurking here since I bought my truck in December. What I have is a 92 extended cab w/ 324k miles. She is a strong runner, and I used this site as a tool to complete the preventitive maintenance she had been lacking. Anyway, here is the problem:
After driving her on a 130 mile round trip, she sat for couple of hrs before I returned to start her up and drive home. Engine fired immediately like always but only ran for 5 seconds. After dying, I smelled that unmistakeable electrical burning smell. I popped the hood and began searching for the problem. I only caught one very faint wisp of smoke on the drivers side of the engine bay. I couldn't find any obviously burnt wires or leads before it got dark.
I returned today to begin troubleshooting. My initial thought was a fusible link. I don't know much about these, so I slit the wires before and after to measure batt voltage. I cut a couple links out and ran a jumper wire between to observe any change; there wasn't any.
The most obvious symptom is that the lights work as does the door buzzer and dome light. When I turn the key to run, none of the message center lights illuminate, the air heaters do not cycle and the engine doesn't turn over. Additionally, on the fat black duck foot looking connector that runs a black and red wire from batt to 4 other wires going to main vehicle wiring harness, there is one empty hole next to the orange wire with a little copper wire sticking out of it. This measures 12v with key off, but I see no loose wire that it is supposed to connect to. Where are all the locations of the fusible links and how do I test them?
Any thoughts? Possibly a smoked PCM or fusible link? Like I said, I can't see any obvious burnt wires. BTW, it has a brand new alternator and Deka battery. I will post pics when I return home. Thank everyone so much for even taking the time to read this long winded post.
-Alan

12valve@heart

Alan, Not sure that I can answer your question about the wires since I don't have my truck or my FSM with me but I did want to ask a couple questions.

First question is will it crank at all or is the ignition non-responsive? You said it won't turn over so I'm assuming that it's non-responsive but if it will crank over, a jumper from the battery to the fuel shutoff solenoid will get it running so you can get it home.
If the ignition is non-responsive, you can still jump the FSS and then jump the starter solenoid to get it going. That's the beauty of the mechanical Cummins - no electronics needed to make it run.

If you don't find a problem with the fusible link, you might check the wiring in the steering column under the ignition switch. I had a burned wire there shut mine down completely.

If you do a search for fusible links in the 1st gen section, you may find what you're looking for. I seem to remember some mention of a blue wire but I may be wrong. You might also post your location in case someone is local to that area and can lend a hand. Sorry I can't give a more specific answer in relationship to your question.