Headlight, Fuel Gauge, Tachometer electrical issues

[lotusmike]

This is my first time posting. I hope someone can help me with some electrical issues I have with my 1965 Elan S2. I live in the upper peninsula of Michigan in the USA.
I have owned my Elan for over 45 years, but now I seem to have some electrical issues I can't figure out.
1. Headlight high beam doesn't work only on DS headlight. I have power to the PS side high beam, but no power to the DS high beam. I don't know how long this has been going on as I hardly ever drive the Elan at night and when I do it is in town so I never use the high beams. There is power going into and out of the connector where power comes from the dipswitch and splits to the RELAY FLASHING MAIN BEAM and the DS high beam, but there is no power coming into the DS high beam light. There is not and never has been a headlight flasher on the steering column, as the European Elans have.
2. My fuel gauge is always pegged on full, (or empty if I reverse the wires on the gauge). It worked fine until recently when I pulled out all the instruments and dashboard to fix the heater core. After I put everything back together the fuel gauge started acting up. When I pulled it all out I carefully marked everything, and I have done this several times before. But I can't figure out why this time, the fuel gauge doesn't work correctly. Any ideas?
3. I had a problem the last couple of years where if I had the headlights on and turned on the turn indicators, the tachometer would bounce. I can't figure out what is causing this. When I bought the Elan in 1975, the generator had been already converted to a Motorola alternator, and it is still a positive ground system. This alternator has worked fine for over 45 years, and is still functioning well now. Also, the ignition was converted to a Petronix electronic ignition system 15 years ago. And the tach was rebuilt to work with electronic ignition by Nisonger Instruments about 10 years ago. It is only recently I have had the problem with the bouncing tachometer. Any ideas?
I hope someone can help me. I have used this website often in the past, but this is the first time I have posted.