No voltage to 7 light fixtures

[JimKrieger]

Acquired a beautiful 2006 RL3500 a few months ago from original owner and now making sure everything works. 6 interior and 1 marker light receive no voltage behind their fixtures according to my multimeter. 5 different circuits seem to be involved. All other lights are perfect. Fuses are all good. Some fixtures have outside rust on screws. Maybe humidity. Checking resistance on all of these wires would be a nightmare and replacing any of them, nearly impossible. Any ideas about how to find and fix on this mature rig?

[Daryles]

Maybe a wire tracer (toner IT/telephone guys use to trace network wiring).

[richfaa]

You may have a problem in your 50 amp input plug . I would take it apart and check all the wiring . We had a similar problem some time back and the plug wiring was poorly done from the factory.

[JimKrieger]

Thank you for two great ideas. Luckily, I figured it out this afternoon except for the two lights above the dining table. The culprits were the corroded fixture switches and also those plastic inline wire splicers which were hiding on the other side of the walls, just inside and below the access holes. The dining table fixtures do have switch corrosion also, but they each also only receive about 6 volts each once the switches are eliminated. Odd. It's as if the normal 12 volts had been split in two somewhere. The other lights on that circuit, however, work fine and glow normally.