Panel lights flicker, gauges go to max

[wafastr]

Newbie here, thanks for all the advice in advance. 1970 Swinger headlight switch works great except when the rheostat is turned CCW so I can see the panel in the dark. That is when the fuel gauge and temp gauge go to their extreme max positions. When I rotate the switch CW to turn the panel lights off, they return to normal. I thought my car was heating up as I drove to work the other day. It seems that excess voltage is going to the instrument panel. The headlights and taillights are unaffected. Hopefully just a switch replacement. Any advice?

 

[RedFish]

The 1 circuits aren't directly related so,
There has to be a problem in the wiring harness or nore likely on the inst' panels printed circuit board.

 

[usdart]

Voltage regulator..it happened to mee just like that.

 

[67Dart273]

Sounds like a ground problem in the cluster, to me