1. Under the dash, to the left of the fuse block, are three bolts with lots of white wires, some green, and a few grey wires. Is that a ground point? Looks like it, but it isn't labeled as such.
2. In that fuse block there is one unused position. There is no indication of any capacity for that position. I want to install a 2 meter ham radio, which is fused @ 20A. Would that be a good point to get power, or is there a better spot? I have plenty of wire on the radio.
sounds like a ground bar, and if you have a meter you can search for power or go to the solenoid on live side with ign off.
JohnH
On top of John's advice, use a test light to check if the fuse position you are looking at is hot all the time or just with ignition switch. As I remember all are not the same. Easy to make a mini Buss bringing a fused lead off the hot side of the solenoid for accessories like the ham radio.
Pierce
On my 1991 U300 the bolts to the left of the fuse block toward the front of the coach are the ground points as you suggested. Be aware that the ignition solenoid is powered by the cranking battery, not the coach battery. A good place to get a lot of power from the coach battery is the master switch by the door. Find the bottom of the switch and run a wire from there to wherever you need power. I'd suggest you take power from the downstream side of the master switch so you can quickly kill power with the master switch in case of an electrical fire, which is pretty common unfortunately. Put your 20 amp fuse right near the master switch so you protect the entire new circuit you install for the ham radio.
Good idea, Scott. That's probably the closest place for power.