There are 3 or 4 grounds built into the original wire harness under the hood. Do all or some of these need to be grounded in order for the ignition to operate in the on and start position? If yes, then problem solved. If no, what are the minimum required connections?

Jo

 

All grounds would need to be connected for all circuits to work. There is no cross-link between the circuits that would allow the car to operate properly with a ground disconnected.