Hello, looks like you have a mess of wiring there, looking at your pictures. That blue clip on the wire, those are not protected from moisture, so I would get rid of it or replace that. Also, I see that ground connection in the first picture that's all rusted, you'll want to clean that up and make sure it's a nice clean connection there. I will post wiring diagrams for the taillamp and license plate circuits for you. This is the 3500-pickup truck, correct? There is a van sub-model for this, why I'm asking. Let me know if any other fuses are popping, or if you need any other diagrams.
I'm not sure where that reddish wire came from, that might be part of a trailer lighting setup.
Okay, they are a part of the trailer lighting. (Last 2 diagrams)
Images (Click to enlarge)
Thursday, February 10th, 2022 AT 12:25 PM