There's this...but like all RV users manuals the electrical is pretty poor.
Swingers Owners Guide
If you haven't removed the lamp fixtures yet, know that on my '94 Bounder, one of mine was in such bad shape (found after I pulled it off and opened it), tossed it because of all the rust and corrosion and bought new...which I happened to find at a little boat repair shop that carried some RV stuff just a few miles from where I was staying. Hah! Pays to stop in at those places. I was really lucky. They've since closed and I've moved on to ownership of a '02 Journey.
With the Journey, had an intermittent taillight/brake light that would occasionally go out and I'd have people pointing it out to me at RV parks as I drove in or out. In that case, I could not find a conveniently available fixture at a decent price and since I have an electronics background, I sort of did a DIY number on all of them as all the sockets for bulbs were in bad condition. Lots of rust and corrosion. Even had to break a blub apart to get it out of the socket:
https://i0.wp.com/chaos.goblinbox.co...?fit=640%2C480
That's all I found wrong btw...bad bulb sockets...so I bought new sockets and kept the fixtures so I could reuse them. There are new ones available but seems a darn waste to throw away the entire assembly when it can be repaired.
Here's the ad free article I wrote about the job. I had a great time working on it...this kind of DIY repair is fun to me.
Rear Running Light sockets replaced!
I also cleaned up and soldered in new LEDs for the middle stop light assembly. A bit more complex, but still fun.