Plus and minus
Two important things to remember NOT to do with a PMGR starter:
Like any other direct-current or DC motor, they will work in the reverse direction if connected improperly. This can do serious damage, so pay attention to your connections when removing the old starter. Although most aftermarket starters have a diode for reverse polarity protection inside the solenoid, these diodes will fail if the wires are reversed.
Permanent-magnet starters do not respond well to the old “tap on it with a hammer” philosophy. You can do serious and irreparable damage to a permanent-magnet starter by rapping on it, even lightly. This can break the permanent-magnets and the unit will have to be replaced.