you will have to disconnect it to stop the engine.

make sure you connected it to the correct side and are not bypassing the resistor.

you will have to figure out where you are dropping power. it could be the fusible link, bulkhead, ignition switch, but doubtful it is the amp meter.

generally that only prevents charging, but start with the bypass first, by putting both wires on one post of the amp meter and see if that fixes it.