Yes & no on them being on the same circuit. They both share circuit 39 (pink/black stripe) which powers all gauges & warning lights, The gauge uses circuit 31 (tan) sending the signal from the sender to the gauge. The choke light for the oil light function uses circuit 931 (dark green'white stripe) sending the signal from the dual terminal pressure switch. This switch also has circuit 250 (brown/white stripe) that is the power feed that at the switchit shares the same terminal for circuit 78 (light blue) which then goes to the carb electric choke. There is something going on if both are tripped. If it was circuit 39 then there would be issues with all the gauges, tach & warning lights.
