12. There are two ways to check neutral safety switch adjustment. One is to ascertain switch continuity—either on or off. Do this with an ohmmeter. Zero resistance (depending on how you set the ohmmeter) means you have a connection, which indicates that there is power across the switch to start the engine. For back-up lights, when you have zero resistance, you have a connection—lights on in reverse. Even with a connection, there can be some resistance.