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Honda Ridgeline Cap

2018

2017

Goal:

Connect the truck cap’s 3rd brake light to your Ridgeline’s brake circuit, so it lights only when you press the brake pedal.

🧰 What You’ll Need:

  • 16–18 AWG automotive wire (red preferred)
  • Crimp or solder connectors (weatherproof)
  • Inline fuse (2–5 A, optional but smart)
  • Wire loom & zip ties
  • Multimeter or test light
  • Ground ring terminal

🚗 Wire Source Location on 2018 Ridgeline:

The 2018 Ridgeline’s taillight/brake wires are LED multiplexed, so you can’t tap directly into the taillights — it can cause false signals.
Instead, use the center high mount stop light (CHMSL) feed or trailer harness as your signal source.

You have two good options:

✅ Option 1: Use the Trailer Wiring Harness (Recommended)

If your Ridgeline has a factory 7-pin or 4-pin trailer connector, it already has a dedicated brake light circuit you can safely tap.

Pin & Wire Info:

  • Wire color: Green/White stripe (Brake light feed)
  • Location: Behind the rear bumper, driver’s side, inside the trailer wiring harness loom
  • Function: 12V signal only when brakes are pressed

Steps:

  1. Locate the 7-pin/4-pin harness under the rear bumper (driver’s side).
  2. Open the loom and find the green/white wire (may be labeled “stop lamp”).
  3. Connect your topper’s brake wire (usually red) to that green/white wire.
    • Use solder + heat shrink or a weatherproof splice connector.
  4. Ground the topper light:
    • Attach the topper’s black (ground) wire to a bare metal bolt inside the bed or frame using a ring terminal.
  5. Test:
    • Press the brake pedal; the topper light should illuminate.
  6. Protect & tidy:
    • Wrap exposed sections with loom and zip ties.

⚙️ Option 2: Tap Into CHMSL Wire (Cab High Mount Light)

If you don’t have a trailer harness, you can pull the signal from the center brake light on the cab.

Steps:

  1. Remove the rear seat back panel or roof headliner edge to access the cab light wiring.
  2. Find the red/white wire leading to the CHMSL.
  3. Splice your topper’s brake wire into that red/white wire.
  4. Route the wire safely through a grommet to the truck bed (seal with silicone).
  5. Ground as before to clean metal.
  6. Test brake pedal → both lights should activate.

⚠️ Important Tips:

  • Do not connect to turn-signal or taillight wires (Ridgeline uses combined signal circuits).
  • If your cap uses LED brake lights, no resistor is needed.
  • Always fuse the topper circuit if running a long new wire (~2–5 A fuse).
  • Seal all connectors against moisture.