Which of the following is NOT a valid voltage check for a starter solenoid?

The correct answer is the voltage between the S terminal and G terminal, as this is not a valid voltage check for a starter solenoid.

In a starter solenoid, the S terminal (signal terminal) is designed to receive a voltage signal from the ignition switch, which activates the solenoid to engage the starter motor. The G terminal typically corresponds to ground or may be related to a specific ground point within the starting system. Measuring voltage directly between these two terminals does not provide useful information regarding the operation of the solenoid because it does not assess the relationship between the signal and ground, or the function of the solenoid itself.

Valid checks include measuring the voltage between the S terminal and ground, which helps confirm whether the ignition switch is sending the appropriate signal when the key is turned. Voltage checks between the G connector and ground help identify issues with grounding. Additionally, measuring voltage drop between the B terminal (the battery terminal of the solenoid) and the motor terminal is a valid method for evaluating the efficiency of the circuit and ensuring that sufficient voltage reaches the starter motor during operation.