2018 3500 Dually side marker lights and under tailgate light out

[crow5716]

So the other day all 4 drw side marker lights are out and the oem little light strip under my tailgate is out.
I still have roof top clearance lights as I believe those are on the same circuit so it's not a fuse.
From the one diagram I was able to find it looks like a white wire with green tracer that feeds those but apart from pulling the whole harness along the frame that's over the fuel tank and def tank I have no idea where to start.
There are no wires or harnesses pinched between the dually leafs and bumpers like I've read about. But all signs lead to a break feeding the rear.
I just want to make sure for some reason that the rear marker lights aren't fed through the abs harness, which is a weird statement, but I just had a problem with a rear abs sensor and it ended up being the wire was broke along the way somewhere so I just spliced into 2 new wires from the abs harness back to the where the abs sensor plugs into and have had no problems with it since. I was getting the dreaded service abs light which disables 4x4 but the only code I was getting was left rear wheel speed sensor out of range. So after that fix, that night I noticed my rear marker lights were out. Which is why I wanted to make sure those lights didn't get their power from that abs harness. lol.
But any help would be appreciated on where to start checking. If someone knows where the two harnesses pictured 3/3 and 6/6 are or had any other suggestions.
Truck is 2018 Ram 3500 DRW 4x4
Thanks in advance for any help.

 

[clifford15]

Check for a stray wire captured in the overload springs on both sides.
It was a problem on earlier versions.

 

[crow5716]

Check for a stray wire captured in the overload springs on both sides.
It was a problem on earlier versions.

I did check that. Plus I also included that in my original post that there were no wires pinched from leaf springs.
?

 

[crow5716]

Still haven't figure this out yet. I tested the plug on one of the dually clearance lights and was getting ground on both terminals. My last resort is to splice in power from the tail lights but I need to make sure I sever the connection going back towards the front incase it is shorted out or broken somewhere that I'm not sending power back that way. I had a problem with a wheel speed sensor that I ended up rerouting that is also in that big harness bundle going back. There has to be a break in the wire somewhere along the frame rail but it's a big bundle of wires all wrapped and impossible to get to in some areas because it goes behind def tank and over fuel tank. From the few vague schematics I found online I can tell it's a white/green wire, but I've check a few places and see multiple white/green wires. Any help would be greatly appreciated.

EDIT: Additionally when this first started happening I could wiggle the wires around near the abs harness and the clearance lights that are out would flicker or work for a bit.

 

[crow5716]

Can anyone suggest a different ram forum that may be more helpful or helpful at all?

 

[crow5716]

guess not

 

[RamDiver]

Still haven't figure this out yet. I tested the plug on one of the dually clearance lights and was getting ground on both terminals. My last resort is to splice in power from the tail lights but I need to make sure I sever the connection going back towards the front incase it is shorted out or broken somewhere that I'm not sending power back that way. I had a problem with a wheel speed sensor that I ended up rerouting that is also in that big harness bundle going back. There has to be a break in the wire somewhere along the frame rail but it's a big bundle of wires all wrapped and impossible to get to in some areas because it goes behind def tank and over fuel tank. From the few vague schematics I found online I can tell it's a white/green wire, but I've check a few places and see multiple white/green wires. Any help would be greatly appreciated.

EDIT: Additionally when this first started happening I could wiggle the wires around near the abs harness and the clearance lights that are out would flicker or work for a bit.

Wiggling miscellaneous wires and obtaining a flicker or intermittent performance of the troubled lights sounds very much like either a bad ground or flakey wiring harness.

The best I can locate for a service manual is a 2012-2017 compliments of Dilligaf.

It might be worth reviewing to locate common grounds, wiring harness routes and confirming if your problem lights do share a fuse or wiring with other devices.

Pdf service manual

Has anyone found a 4th generation service manual in a PDF format? If so can you please share the link? I can't get the McFall one to work on my phone. Thanks!

www.ramforum.com

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