Not knowing any more than the small tidbits of information that you have given us it would be nice if you can share a little more information. Have you taken your car wash operator’s best friend and checked the voltage on the motor starter when the rotary switch is in the Rinse position? Is the pump motor running, if so, disregard checking the voltage at the motor starter with your car wash operator’s best friend. If the motor is running but no water is coming out take your car wash operator’s best friend and check the voltage at the rinse solenoid. If you have voltage at the rinse solenoid then the problem is with the solenoid valve. If you don’t have power at the rinse solenoid start at the rotary switch with your car wash operator’s best friend and trace the wire back to the rinse solenoid