Pretty good advice above.
100 amp panel with a solar controller may put out 8 amps.
The "solar ready" feature in my Kodiak Cub is socket on the outside with a 10 amp fuse connected to the battery on the tongue.
An owner with a newer model says there is also a connector on the roof and the two wires run to a box in the front pass through and then to the front battery. I don't know the capacity of the wire and fuses in the new system.
I doubt your Colman has much more than that. You would still need a panel and solar controller. If you wanted more than 100 watts you probably need to run bigger wire with bigger fuses.
I wish you good luck and happy trails ahead!