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ODWH OVERDRIVE WIRE HARNESS Installation Instructions

Click here to download the full guide with images

These instructions will help you install and test your new Overdrive Wire Harness. Please read completely before attempting to install.

The ODWH is designed to replace your overdrive wiring which may have become damaged due to age and use.


  • Intended for use with 6-Volt or 12-Volt electrical systems and Borg Warner overdrive solenoids.
  • Main Harness connects the OD Relay, Kickdown Switch, Solenoid, and Shift Rail Lockout Switch/Governor.
  • Additional wires connect the OD Relay to battery power and ignition components in a variety of configurations.
  • A wide assortment of crimp terminals is included to accommodate the variety of connections originally used in the overdrive system.
  • Main Harness loom and wires can be shortened at the relay and overdrive ends as necessary. The loom resists fraying when cut with regular scissors, but the cut end may also be melted using a heat source if desired.

Installation: Before you get started always disconnect your battery.

  1. Follow the main wiring diagram on the enclosed sheet. Depending on your relay type and whether your relay connection is a 3-wire or 4-wire type, also follow the appropriate inset on the reverse.
  2. If installing in a vehicle that did not have an overdrive previously, choose either a three or four wire connection, and follow the corresponding diagram on the reverse of this sheet. A reason to install using the four-wire diagram is that the current load of the overdrive solenoid during engagement (30A for 6 volt; 15A for 12 volt) will not be passed through the ignition switch.
  3. Note that on some overdrive solenoids and overdrive governors, the leads are permanently attached, and where present, these flying leads should be preserved and reused as they are part of that component and not the harness.
  4. The pre-terminated junction on the harness connects to the OD Kickdown Switch. Be certain that the wires are connected to the Kickdown Switch according to the colors in the diagram.
  5. The end of the harness with the red, white and blue wires connects to the OD Relay and Ignition Coil. Connect red to Relay TH.SW., blue to Relay SOL, and white to Ignition Coil terminal or Distributor as shown in diagram.
  6. The end of the harness with the blue, orange, and yellow wires connects to the electrical components on the overdrive itself. Connect blue to OD Solenoid terminal 4 (or flying lead blue or green). Connect orange to OD Solenoid terminal 6 (or flying lead orange). Connect yellow to the Overdrive Shift Rail Lockout Switch. An additional piece of yellow wire is included to connect the Overdrive Shift Rail Lockout Switch to the Overdrive Governor. Some overdrives to not have a Shift Rail Lockout Switch, and in this case, connect the harness yellow directly to the Governor.
  7. Be sure that the wire connected to the OD relay BAT terminal must be 14AWG or larger. A 5-foot piece of black 14 AWG wire is included for this connection.
  8. Reconnect the battery and test operation.

Click here to download the full guide with images