Hello. You check the coils with an ohmmeter. They should be around 70/75 ?. I don't know why there are 3 ends. In any case, where the resistance will be around 70 / 75?, connect the power supply, 12V battery, insert a drill (not deeply) into the coil, for example, connect the voltage - the drill should be pulled inside.
Hello. Check these two pins parallel to each other with a meter in the 200 ohm range, it should show several tens of ohms. If it does not show anything, the coil is unfortunately a loss. This third pin is the protective one. At a voltage of 12V, it is rather unnecessary.
