Wiring and Connectors in Pinball Machines

Usually there are two types of wires/connectors used in a pinball machine. One for all low current connections (i.e. switches or logic) and one for high current connections (i.e. coils). See Voltages and Power for details about the different voltages and power requirements.

Warning

If you are unsure ask a professional electric engineer. This guide does not provide all information needed to design and operate a high-voltage/high-current system in a pinball machine. Use this at your own risk. Electricity can be dangerous and might kill you or burn down your house.

High Current

High currents require proper wires and connectors. Otherwise stuff might get hot and start a fire. This applies to coils and in some cases also to lights (if you power more than one light with a wire). In general, everything above 1A current should use thick wires.

For high current wires you usually want to use AWG 18 or smaller (thicker). The metric equivalent would be 1mm^2 or more. Also consider the resistance per meter/inch of your wire and calculate the voltage drop in advance.

Your connectors should also be spec’d for your expected current. Most 100 mil Molex connectors allow up to 1A which definitely is not enough for coils. For that reason, 156 mil Molex connectors are used for coils. Usually, they are spec’d for 7A (depends on housing and crimp). If you need more than 7A use multiple pins.

Molex part numbers (KK series):

  • 2 positions: 09-50-3021
  • 3 positions: 22-01-2037
  • 4 positions: 22-01-2047
  • 5 positions: 22-01-2057
  • 6 positions: 22-01-2067
  • 8 positions: 09-50-3081
  • 9 positions: 09-50-3091
  • 10 positions: 09-50-3101
  • 11 positions: 09-50-3111
  • 12 positions: 09-50-3121
  • Crimps: 39-00-0342 or 08-52-0072

Low Current/Logic Power

For logic power you don’t need thick wires. Typically, AWG 20-24 or 0.5mm^2 to 0.25mm^2 is used. Connectors are usually 100 mil Molex connectors.

Molex part numbers (KK series):

  • 2 positions: 22-01-2027
  • 3 positions: 22-01-2037
  • 4 positions: 22-01-2047
  • 5 positions: 22-01-2057
  • 6 positions: 22-01-2067
  • 9 positions: 22-01-2097
  • 10 positions: 22-01-2107
  • 11 positions: 22-01-2117
  • 12 positions: 22-01-2127
  • Crimps: 08-51-0108 or 08-50-0114

There are also a lot of very cheap no-name replacements for 100 mil KK which work just fine since there should not be any high current on those connectors.

Sourcing Connectors

Those connectors and crimps can be purchased from Digikey or Mouser. Additionally, you can buy those at your pinball supplier but they tend to be quite pricy.