Resistor & Diode Installation Instructions For Main & Reversing Contactors All contactors we offer are unidirectional; both the main contacts and the smaller coil connections. So it does not matter which side you connect your cables to.
The pre-charge resistor is also unidirectional. Attach it across the large poles.
The coil suppression diode goes across the small poles. It is directional and will be ruined if installed incorrectly. On one side of the diode is a silver stripe. It should have a red heat shrink on the same side, shown as #1 at right. The striped side of the diode must connect to the same side of the small coil connections on the contactor as the color wires referenced below for your vehicle.
If these wires have been changed, or you have a different type of cart, the stripe side of the diode will be on the hot side of the circuit, or the key side. The other side runs to battery negative.