I bought an Engo 10000S winch a few months back, installed the winch itself minus the wiring but had put off the solenoid box and wiring until just recently with the warmer weather. I wasn't happy with the supplied plastic solenoid box that looks like it won't be very water resistant, undersized wiring (appears to be 6 gauge), nor the way the wiring exited the box at the back interfering with the grill. I decided to scrap the whole mess and rebuild my own box.
So, I bought a steel Hoffman enclosure, screw top, 6"x6"x4" (after trying another size I had on hand), and ditched the cheap double solenoid setup provided and bought a nice water proof sealed single 500A rated unit from eBay (Runva brand) for about $70. I got the Hoffman enclosure there too for about $25. Next I bought some made in the USA 2 gauge welding cable, also on eBay and some 2 gauge terminals, and an ANL fuse block with 500A fuses from my go to wiring supplier, Waytek. I wanted a fuse at the battery for the winch since I've heard a few horror stories, and while a switch would be nice, finding one that isn't too large and rated for 500A was an issue, so just a fuse for now.
All the wires were cut to the length needed to avoid extra wiring rubbing and chaffing. Crimped, soldered, and sealed with a good double wall heat shrink that has the glue membrane to seal out moisture.
Finished up the wiring install today and tested it out, all seems good to go.
I have to throw on the wireless receiver I got with the winch but that should be easy enough and will sit inside the enclosure, will have to see how the range is, since it's an all metal box now. The Hoffman enclosure gives me much more piece of mind, it's very sturdy, waterproof and you can remove and replace the top without worrying about stripping the cheap plastic. Even if I get a new winch someday because this one doesn't last, I can reuse this solenoid box, it should last a while.
All in all, happy with how it turned out, I wouldn't change much if I had to do it again. Pics attached.