ok if you have a key switch then the ground should go from the battery - to the key switch then to one side of the starter button then the other side of the starter button to one side of the solenoid same side of the solenoid that goes to the starter
the other side of the solenoid should be power from the battery to the solenoid thick wire and also small wire same side two terminals so solenoid has 4 terminals all together
hope this helps if not lemme know
but def look for some diagrams and trace all wires and make sure the motor is grounded to the frame use a test light connected to the power side and touch the motor and frame to see if its grounded good
the other side of the solenoid should be power from the battery to the solenoid thick wire and also small wire same side two terminals so solenoid has 4 terminals all together
hope this helps if not lemme know
but def look for some diagrams and trace all wires and make sure the motor is grounded to the frame use a test light connected to the power side and touch the motor and frame to see if its grounded good