The fsm has a description of the current flows by device just after the wiring diagram, in the tranny section iirc. Three main power paths. Batt, od off relay, valve is one, for the solenoid power. Batt, ign, shifter switch, od off relay coil power, temp switch, gnd is the second, the o/d relay control circuit. Batt, ign, od off relay, dash light is the third, the indicator circuit. The way the relay is set up, either the light or the solenoid valve has power.

Not responsible for advice not taken...