Daleb

When I got the truck the fuel pump was in the fuel tank and was powered by the battery and the relay was triggered by the original connection of the ecm. When I put a fuel gauge in the truck I only had 6psi fuel pressure from idle to wot it never change so I bought a fass titanium and 1/2 inch fuel line. The pump is ran off the battery and the ecm triggers a relay and I run about 18psi. Now as for the head light problem they come on with the key on. With the key off they come on when I put the parking lights on. If I pull the head light fuse they stay on really dim. If I disconnect the day time running light module the lights go out but if I turn the head light switch on it still kills the motor if running. If I take the #1 50amp battery fuse out I can turn the light switch on with out killing the motor but the head lights are still on.Also I have no blower motor or speedo but all other gauges work and I'm not sure if the problems are all related.I am in the process of finding a good 2nd get mechanic because I think this electrical stuff is beyond me.

Amsoil has this

The worst wires in the damaged pdc I have are melted at the wire thats goes to the fuel pump relay. I wonder If the damage was down when one of the original engine mounted ecm powered fuel pump failed and heated JC2. Maybe it was slowly deteriorating over the years until it failed. Might explain why there seam to be a bunch with the same damage. All my fuses in the pdc where the proper size but who's to say what was in there over the years. Dale

thanks I will try to see if lights work normally with key off.No the truck does not have fog lights. Dale

Good news I got the truck running was a loose plug in the engine line out harness. Bad news is the head lights stay on and if I turn the head light switch on the truck quits. Also getting code p1689. I cleaned all the grounds as I installed the new harness. The head lights are on as soon as the key is on and the high beams don't work anyone know what other grounds could be the problem or might this be another problem? Dale

I was just thinking if JC2 goes bad should we not be able to bypass it and run the wires to a new fuse block and join them there. Or does JC2 serve another purpose that could not be served by fuses?

Well there is a 98 24v in my area that just had his joint connection 2 burn up. That makes 2 total failures in the last few months also I have one here off a parts truck that got hot enough to blacken the plastic and have looked at a few others when I was shopping for my new harness that were the same. Im starting to see a pattern here that I'm not liking. Wonder If the early 24v are going to start having issues you all might want to pull the pdc off at the bottom and inspect joint connection 2 for signs of melting plastic.

I thought the extra stuff under the dash was for the starter but its not because the starter works without it being hooked up. the light blue wire on the steering column is what its hooked to. Im going to have to trace the wires and see where they go. Cummins mechanic told me what to test on ecm to see if its getting power I will do that tomorrow.As for the wipers A bad ground can cause that sort of problem they seem to work fine now. This truck is quickly working its way to a ppump.

Im going to check all the connections today because I had the connectors unplugged. The lift pump is powered off the battery and uses the original factory connection to turn it on through a relay

Well hooked the batteries back up. The good news is that joint connection 2 stayed cool the bad is no wait to start light or fuel pump and could not pull any codes so looks like I might have to send my ecm for repair. Lucky these wonderful site has a list of good repair shops. Dale

I must say thank you to you all here for your knowledge and patience I really appreciate it. Dale

I looked at the old pdc and the worst melted wire came from fuse 3 eng control 2 and then to the grid heater relay. The relay was in bad shape when I removed it was cracked badly but was still working. Could it have back fed up into the joint connection 2 and caused the damage weather instantly or over time? Dale

This might be it . I remember last summer shortly after I got the truck I was looking into the A/C not working and I pulled the fuse and one side of the fuse was broke and seized in the connector. At that time I remember something drawing my attention to joint connector 2 but I have a bad memory and can't think of what it was. The only other thing that I noticed when I was replacing the wiring harness from the pdc to under the dash is that someone has installed a fuse block thats feeds a solenoid and is powered from the battery. I think someone has made a starter circuit but won't know till the battery is hooked back up to see if I'm right. If they bypassed the starter circuit makes me wonder what happened to make them do that. They left the starter fuse in and the relay so If they have bypassed the pdc stating circuit should they not have removed the fuse and if that is the case guess I should track those wires down and see what they at the end. Dale

One of the heavy equipment mechanics at work said that bad ground could easily put the extra stress on the pdc to cause it to burn up. The day this happened the wipers started to come on by themselves at the time I thought it was a bad switch but that is also a sign of stray voltage from a bad ground. Im hoping thats what caused it because I have found no other explanation that's why I have been paranoid to hook the battery backup and trying to troubleshoot before I do. Dale