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Rad Power Bikes Production Site

RadCity Wiring Harness Replacement Guide

The RadCity wiring harness runs through the downtube and connects various electrical components to the controller. The wiring harness can be replaced if you are instructed to do so by Rad Power Bikes Product Support.

Follow the steps below to replace the wiring harness on a RadCity.

Tools Needed:

  • Flat side cutters
  • Flat head screwdriver
  • String a few inches longer than the length of the downtube
  • Electrical tape
  • A few zip ties
  • The replacement wiring harness from Rad Power Bikes
Remove the Old Wiring Harness
  1. Get the bike ready for maintenance. Turn off the bike, remove the battery, and press and hold MODE to discharge remaining power.
    RadCity turn off bike.gif
  2. Unplug the connectors at the front of the bike.
    1. Snip the zip ties securing the cables.
      Snip zip ties.gif
    2. Unplug the silver metal display connector. Untwist the metal portion of the connector, then pull each side directly apart, without twisting, to unplug.
      RadCity unplug display.gif
    3. Pull each remaining connector directly apart, without twisting, to unplug.
      RadCity - unplug all connectors.gif
  3. Unplug the wiring harness connector.
    1. Unseat the rubber grommets at the upper and lower cable openings of the downtube (shown below). Use a flat head screwdriver and careful pinching movements to carefully unseat the rubber grommets. Be careful not to damage the grommet during removal. Snip the zip tie securing the cables at the bottom of the downtube, if needed.
      RadCity - remove grommets.gif
    2. Turn the handlebar and feed the wiring harness into the downtube. Locate the wiring harness cable at the front of the bike and gently feed the cable into the upper cable opening of the downtube.
      RadCity feed in wiring harness.gif
    3. Access and unplug the wiring harness connector. At the bottom of the downtube, carefully pull the wiring harness cable until the connector is out of the lower cable opening. Use caution to avoid unplugging the connector while inside the downtube. Once the connector is out of the downtube, pull each side of the connector directly apart, without twisting, to unplug.
      RadCity - unplug wiring harness.gif
  4. Remove the wiring harness from the downtube.
    1. Secure the string to the connector end coming out of the lower cable opening. Tie and tape the string to the wiring harness connector end to keep it securely attached to the wiring harness . The string will be used to help move the new wiring harness through the downtube. Insert the connector end into the lower cable opening of the downtube.
      RadCity - tie and tape string.gif
    2. Remove the wiring harness through the top of the downtube. Carefully pull the wiring harness out of the upper cable opening and through the grommet, ensuring the string comes out of both cable openings and remains inside the downtube.
      RadCity - remove wiring harness.gif
    3. Remove the string from the wiring harness. Allow the string to hang outside of both cable openings. Recycle the old wiring harness according to local rules.
      RadCity - recycle wiring harness.gif
      Continue to the next section to install the new wiring harness.
Install the New Wiring Harness
  1. Locate the new wiring harness and orient it so the side with fewer connectors points toward the back of the bike.
  2. Insert the wiring harness into the downtube.
    1. Secure the string to the new wiring harness. Tie and tape the string coming out of the upper cable opening (shown below) to the single-connector side of the new wiring harness.
      RadCity - insert connector into downtube.gif
    2. Pass the connector into the upper cable opening of the downtube. Pass the connector end through the rubber grommet at the upper cable opening and gently push the connector into the downtube. At the same time, gently pull on the string at the lower cable opening until the connector moves out of the opening. 
      RadCity - access connector.gif

      Do not use any tools (other than the string and tape) to assist in directing the connector end out of the lower cable opening. Tools like pliers, screwdrivers, etc. can easily damage the connector pins and housing, especially when inserted from the lower cable opening upwards into the downtube. 

  3. Connect and adjust the wiring harness.
    1. Connect the wiring harness to the controller. Remove the tape and untie the string from the connector end. Locate both connector ends and ensure the connector end passes through the grommet. Line up the internal notch and pins (and external arrows) and press directly together, without twisting, to connect.
      RadCity - connect wiring harness.gif
    2. Insert the connector into the lower cable opening of the downtube. Double-check that the connector is secure and gently pass the connector into the lower cable opening. At the front of the bike, gently pull the wiring harness cable to add cable slack.
      RadCity - insert connector.gif
    3. Reinstall the rubber grommets. Gently work the grommet around the opening until fully seated.
      RadCity - install grommets.gif
  4. Plug in the connectors.
    1. Plug in the display connector. Locate the connector ends with the silver metal portion. Line up the internal notch and pins (and external markings) and press directly together, without twisting, to connect. Then twist the metal portion together fully.
      RadCity - connect display.gif
    2. Plug in the headlight connector. Trace the cable coming from the bottom of the wiring harness junction, and locate the matching connector end coming out of the headlight. Line up the internal notch and pins (and external arrows) and press directly together, without twisting, to connect.
      RadCity - connect headlight.gif
    3. Plug in the remaining connectors. Plug in all other connectors at the front of the bike. Locate the wiring harness connector ends and the matching connector ends. Trace the cable from the part to the connector end and ensure the connectors match. Line up the internal notch and pins (and external arrows) and press directly together, without twisting, to connect.
      RadCity - plug in all connectors.gif

      Do not plug in a connector to the wiring harness if it does not match in color and shape. Doing so could cause irreparable damage to the connector, the part, or the wiring harness.

    4. Secure the cables with zip ties. Trim the zip ties to be flush and smooth.
      RadCity - zip tie cables.gif
  5. Check that all cables are free from any moving parts. Rotate the handlebar to ensure it can move freely and that there is enough cable slack.
    RadCity - check cables.gif
  6. Reinstall the battery, test the bike fully before riding, and ride Rad!
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