Try changing the headlight switch.
This also happened to me and it only got worse. The dash electronics started going crazy. The speed needle would not read correct, the idiot lights all flashed on and off. I got stranded and found out my alternator was going and needed to be replaced.
If this is an electronic unit, the heat generated after the lights are on for one half hour, is affecting the intergrity of the electronic circuit board.
The wires for the fog lights and speedometer are probably rubbing together somewhere behind the dash, the insulation is most likely worn on both the wires. I t will cause a short if it continues. Check the wires for worn insulation.
relay
The SS had a different dash, with gauges, not idiot lights. I would contact Year 1, online, as they make reproduction parts, and will have everything you will need, from the dash, to the wiring harness you will need to change, to all the new sending units, you will need. The SS, was unique that year.
why would a speedometer and odometer not work on a suzuki motorcycle?
you can go to speedometer and out of speedometer
They would be shorter and that would affect speedometer accuracy.They would be shorter and that would affect speedometer accuracy.
The speedometer was going very high up.
if you want to "you are idiot", you would say "babo ya" or if you want to say just idiot, you would say "babo" source by Korean
Accurate or precise are one and the same to which the automotive speedometer would never be.
If the speedometer is not working but the odometer is, I would suspect the dash cluster is at fault. If both speedometer and odometer are not working I would suspect the speed sensor on the transmission is at fault.