Troubleshooting Curt Universal Tail Light Wiring Kit Installation

Updated 04/15/2026 | Published 04/10/2026

Products Featured in This Question

Curt Universal Tail Light Wiring Kit for Towed Vehicles - 4-Way Flat Connectors

(132)

$92.62

Roadmaster Brake-Lite Relay Kit for Towed Vehicles

(761)

$51.66

Question:

Bought the c63cr for a Toyota tundra. I used a tester to make sure I was making the right connections however I have no power to the turn signals when connected to my motor home and even tried on another vehicle. The turn signals instead work on the brake/tail light. I believe this is 3 wire because I have brake/tail on one bulb and a yellow turn signal on another. Please advise.

asked by: Joshua S

Expert Reply:

Hi Joshua, your Tundra uses a 3-wire system (separate brake and turn signals), while the 4-flat coming from your motorhome is a 2-wire system (combined brake/turn). The Curt # C63CR is designed to handle that, but only if it’s tied into the correct wires on the truck.

On your Tundra, make sure you’re connected to the actual turn signal wires (left/right) and not the brake light circuit. With separate amber turn signals, it’s very easy to accidentally tap into the wrong wire.

If your connections are correct and you still have the issue, you’ll need to add a brake light relay # RM-88400. Without it, the brake signal can override the turn signals when connected to the motorhome.

I’d start by double-checking your wire taps, that’s the most common cause here.

expert reply by: Robin H