Nothing can cause problems with a charging system more than corrosion. It is something that needs periodic maintenance wherever you typically find a battery, such as in your car. Even if you have a maintenance free battery, you still need to clean the terminals every once in while or eventually you will lose contact with the battery. In an RV environment this will usually lead to undercharged batteries or no charging at all. Not things you want to become issues when you are in the boonies.
This is even more problematic with the way that the wiring is done on the North Trail.
What you are looking at in the picture is what I will refer to as a junction block. It consists of two 30 amp fuses connected with a copper bar. The left side in the picture is the positive battery cable, the right side the 12 volt feed to the converter and fuse panel inside the trailer. The smaller red wires are providing power to the braking system and brake lights and turn signals. The problem here is that this is mounted exposed on the front of the trailer. It does have the rubber boots that kind of cover it but as you tell from the amount of rust on it, it gets fairly wet if you are driving in the rain. Eventually this was going to cause a major headache, so as part of my upgrade to the solar charging, I decided I needed to do something about this.
I think the reason that the fuses are exposed like this is because the underbelly of the North Trail is enclosed. If the manufacturer had placed this behind the frame it would be covered and you would have to take down the plastic underbelly material to gain access. I would think an enclosure or box to house this arrangement would have been better but some things in the RV world are shall we say, a little deficient. This mod cost me about $20.00 so it wouldn’t have been too much of a burden while the trailer was being built.
This what my “junction box” ended up looking like. The plastic box is just a plain waterproof enclosure purchased from Home Depot. The conectors on the sides I had to drill holes for and they tighten around the wires to create not quite a waterproof seal but pretty close. I re-used the 30 amp fuses after I cleaned them up. This is what it looks like with the cover on.
The biggest obstacle with this mod was that the wires on the trailer side of this block were VERY SHORT. I had a hard time to get them into the box but there was nothing I could do as they go back through the frame so changing them wasn’t an option. While I don’t expect to have this remain corrosion free forever, it should stay dry and holdup alot longer than what was there. 
