Engine Running Signal

I am rewiring the whole car, so the switch will work how I need it to. I dont need the lamp since I have a gauge. I will run 12V from Q2 to the positive side of a relay coil, the negative side will run to the oil pressure switch. So when the key is on but the engine is off the switch will be made (Normally closed switch) thus the relay coil will be activated. When the engine is running and oil pressure is made the oil pressure switch will turn off and so will the relay coil.

SO a relay with a NO and a NC contact will work perfect. When the relay is on (no oil pressure) the NO contact will be made, which will run to the light on the rocker switch telling me or whoever that the engine can be started. When the engine is running and the relay turns off, so will the light on the rocker switch, meaning the engine is running so dont try to 'start' the engine since its already running.

I am going to take it a step further and wire the relay in to the starter relay circuit so the starter circuit will be dead when the engine is running so there is no chance that the starter can be energized while the engine is running.

Simple relay logic.