Newby here, I just bought a 99 dually with an apparent wiring issue! I replaced the entire fuse box and harness this weekend only to barely touch the positive and have smoke start rolling out the fuse box!:banghead: I opened up the fuse box to peek under it and found the burnt wire is from the J/C 1 port. What is it,and how do I fix it? The truck was running before this but had the parking lamp on engine shut off problem. Any help would be greatly appreciated!

You need to find the shorted wire first of all. Pull the fuse box and check the underside for anything that even resrmbles a short. In other words look for a burned spot an the wires and connectors.

  MnTom said:

You need to find the shorted wire first of all. Pull the fuse box and check the underside for anything that even resrmbles a short. In other words look for a burned spot an the wires and connectors.

The burnt wire is J/C 1 pin 28. It must be pulling all it can get because I barely had the battery connected and it lit up fast! I have gone over all the grounds and cleaned them and put dialectric grease on them and all connections that I have touched to date. Thanks

Tell me where J/C 1 pin 28 is. If it is getting that hot then you need to look as far down stream as where the melting started. If it is in a connector then look to see where the other end goes. Chances are it is going to be something simple so don't over think it.

  MnTom said:

Tell me where J/C 1 pin 28 is. If it is getting that hot then you need to look as far down stream as where the melting started. If it is in a connector then look to see where the other end goes. Chances are it is going to be something simple so don't over think it.

J/C 1 pin 28 is the the first wire if you are reading left to right and top to bottom, it started to burn right at the fuse panel and went maybe 8-10 inches out of the panel about at the point where the harness has the first y in it where it splits to drop down the fender well under the brake booster and the rest of the harness feeds towards and through the firewall. Hope this helps! Thanks:pray:

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Anyone else out there have some information for me?:pray:

Ok, found the burnt wire went to the grounding point behind the drivers side headlight! Fixed that and we believe it was caused by a shorted out heater blower motor. We will be testing that in the morning.The thing I can't figure out now, is that the truck would run fine before we found the wiring issue, now that we have that figured out it will crank but not fire. It is showing the dreaded No bus code but it did that before and it would run. The other thing is that the lift pump seems to go through that 25 second cycle everytime I turn the key. Any help would be GREATLY appreciated! Thanks

Hold on a sec. Blower motor ground is in the cab at the driver side kick panel as well as the headlight switch ground. This would also cover the ground for instrument panel as well.

We got the the truck running this morning! We cleaned the those 2 hot lead wires(Black&Black w/white stripe) attached to the positive battery cable on the drivers side,what are those, they go to 2 coil like things mounted to the inner fender well? Now we still have the fuses and relays pulled for the lights and the blower motor and we will be testing those circuits today.Mopar Man...where did you say those grounds were for the blower and lights? I have not found that point yet.Thanks guys, I will post more info as it comes in and pictures when I finally have her on the road.

Those two "coil like things" on the inner fender are the grid heater relays. They are not critical to get the engine running.