Hello, I recently bought another truck non running of course, price was good and truck is clean and no rust so I figured why not. I’m going to try an explain everything thoroughly start to finish. The previous owner (diesel mechanic) bought it off a customer and tried to get it running. He lost interest. He had told me the only way he got the truck to run was he cut the bus wires in the injection pump.

When I started investing I found the dash harness to be the wrong one, truck is fully loaded heated leather and had a basic dash harness in it. It appeared someone swapped the dash out. (Will make sense later keep reading)

I found the correct dash harness for the truck part # according to mopar website and the supersedes/cross reference, I just got everything installed with a new dash and buttoned up. I reconnected the bus wires on the injection pump, truck starts and runs fine now. Here’s the problem I am having, the dome light is getting back fed from somewhere, stays barely lit, even with CTM unplugged, door switches unplugged, dash main connector unplugged, the only thing that shuts it off is the smaller dash connector, or pulling the connector off the headlight switch, here’s what’s even weirder, if I turn the dome light on from the switch it shuts off, and I am able to turn the parking lights on without the fuse blowing under the hood (parking light fuse) 15amp. If the dimmer is set or dome light off when I turn the parking lights on it blows the fuse. I have unplugged rear harness, connector on cab mount, ctm, ignition switch ect, replaced headlight switch with known good one, I have even swapped CTM from my other truck, I was very very tedious when I put the new dash harness in and plugged all my connectors in, I had the dash set up on a table ect, for some reason I think this is why the dash harness was swapped out before, previous owner thought it was that. Also the overhead console lights don’t come on automatically unless I click them on at the lense. If anyone has suggestions I would greatly appreciate it, I also made sure the dash harness color coded wires were all the same. And connectors were fully seated Thank you

Wow! I have to commend your perseverance to get as far as you have. Good description of your issue.

I don't have much offer at the moment. I think you may be right in regarding a previous owner thinking there was a dash wiring problem. Electrical ground problems, back feeding problems, and short circuit problems can be some of the most challenging electrical issues to solve.

I think I would put my first focus on finding what is causing the 15 amp park lighting circuit fuse to blow under certain circumstances. You find that, then maybe everything else will fall into place.

Also, I would look for any evidence of other accessories (especially lighting) that may have been wired by a previous owner.

Do you have a wiring diagram to work from?

• John

Update: I swapped the main fuse box and still have the same problems

Welp I figured it out. I accidentally swapped the common ground plugs/junction connectors behind the dash. Added pictures and circled.

Glad you got it figured out. Are you saying that there are two female connectors and two male connectors and that they will interchange?

• John