I'm having a similar problem with my dash also. everything works fine until I turn the lights on, then the gas gauge goes to empty, the left turn tight comes on, a couple of dash lights work when the low beams are on, no dash lights with high beams except the left blinker is on and the high beam light is on when the low beams are on
. I've check all the bulbs, the printed circuit isn't in the best shape. I'll be building an ammeter dash later so I'm not wanting to buy a new printed circuit for my idiot light dash.