Would there be any harm in running my cables from the panels to the charge controller on the outside of the trailer?? My roof is not conducive to running the cables where I want to run them, so I thought maybe I could do an alternative routing??

I can mount both of my panels on the roof, secure the cables to the roof top, then run the cables down the front of the box along side the vertical support strips that run up the sides of the trailer. I'd secure them with 1/2" metal/rubber cable clamps and most likely heat shrink sections between the cable clamps for security. Everything would be sealed up with silicone.

I have an entry gland that I could run through the front diamond plate, and then directly to the controller.

Would this work, or would be asking for a disaster?? I already ran battery cables through the diamond plate, and have had zero leaks or water intrusion so far.

With some of the fasteners that are out there now, I'd run it in conduit. Just make sure where you run it won't interfere with anything. Open doors, pass-through, storage, connections, etc.

It's gonna be 100% outside of the trailer, until it goes through the front to connect to the charge controller.

I like the conduit idea, I'm gonna look into that. Thanks!!

As long as the cables and connectors are weatherproof rated, you should be fine.
I routed my solar cables on the outside and into the front box, where my controller sits.

Sweet!! That's good to know!! My OCD will require me to use way more fasteners than you did, but at least I know it'll be fine!!

Thanks for the pic, too!!

I understand the OCD, but I have to keep some slack in the cables to allow the roof of my trailer to raise and lower. the fasteners are held in place with 3m VHB tape, they have stayed put after thousands of miles and in all weather conditions.

Got it. I have the VHB tape, but I'm gonna screw 'em down, anyways. We have some pretty extreme summer weather, I don't want to take any chances!!

While I don't own it any longer, that's exactly what I did with mine, and had no issues.

All cabling was outdoor rated. Had it for almost 10 years, no issues that were related to solar or
the cables. (Mice and batteries, lots of issues.)

I got all Renogy parts for the whole system. I'm pretty sure their cables are outdoor rated, but I'm gonna check to make sure.

Thanks for the info, now I'm sure it'll work!!

Renogy is pretty decent stuff for being value-priced, I have a couple Renogy based
solar systems at my cabin going on 4 years without issues, including a 170AH  Renogy
branded LiFePO4 battery.