Deleted my first reply...had a thought, but then thought it through and retracted it. I re-read your post - the bike Starts & Runs but the gauges aren't working properly. Certainly sounds like a connection problem somewhere but upon reflection, I don't think there are that many different wires coming off of the switch.
There's a wiring diagram in the back of the Service Manual...if the failing components can be isolated to a single source feed (relay or connector) you may find the answer by looking there.
Certainly a new one on me - sorry I couldn't be of more help.
Ps: the electronic copy of the Service Manual can be found via a link at the bottom of any of Bishop's posts.
Again, Good Luck.