Bill - I re-wired most of my boat last spring as well, everything but a few cabin lights. Reason I didn't do them was that 1) the lights were all working fine, and 2) it would have meant taking off the overhead cabin liner, and I was already very deep into just about every other part of the boat (engine compartment, hanging locker, mast boot, head sink compartment, electronics locker in front of the nav table, etc). I also found the electrical panel had to be replaced.
As I recall, the wiring for the cabin lights went from the panel to the bus under the nav table, and from there to the hanging locker just forward of the nav table, down through the chase that runs forward to the right of the sole, exiting in the small locker across from the mast boot. This was a real pain to work with, b/c all the wires that used this chase (holding tank indicator light, shower sump pump, cabin lights, mast wiring, antenna, etc) were taped or cable-tied together every foot or so. I ended up cutting all the wires, and pulling out all of them, then re-running new boat cable (with jackets) the length of the run.
A good trick is to disconnect the boat batteries, and use the bus panel under the nav table as a source of power - rig together enough D size batteries in series to get a 12 volt system (you can buy battery holders at Radio Shack), then wire this battery to the cabin lights post on the panel bus (I believe it's position "B"). If the lights then work, you know the problem is from the bus to the electrical panel (probably just a bad switch). If they still don't work, you have a bigger challenge, but I don't see why they all would fail.
One warning - DO NOT USE THE BOAT'S SHORE POWER WHILE DOING THIS WORK! Instead, rig up a dockside extension cord with a worklight, rather than using the ship's shore power connections. Reason is that the AC power bus panel is right next to the DC power panel. One slip and you could be off to that great marina in the sky. Whenever I worked on the electrical, everything was completely disconnected - I even had the batteries off the boat, and used the 8 "D" size batteries for testing (using a voltmeter, ammeter and ohm-meter).
Good luck!