Troubleshooting Loss Of Tail Light Function After Installing A Diode Kit In A 2023 Ford Bronco

Updated 11/06/2023 | Published 11/05/2023

Products Featured in This Question

Roadmaster Smart Diode Kit for Variable Voltage LED Tail Lights

(335)

$143.27

Hook Probe Circuit Tester

(66)

$13.42

Roadmaster 4-Diode Universal Wiring Kit for Towed Vehicles - 7-Way to 6-Way Coiled Adapter Cord

(3397)

$161.90

Roadmaster Smart Diode Kit for Variable Voltage Incandescent Tail Lights - 7-to-6-Way Adapter Cord

(151)

$335.02

Roadmaster Smart Diode Kit for Variable Voltage LED Tail Lights - 7-Way to 6-Way Adapter Cord

(335)

$265.46

Question:

Why don’t the tail lights illuminate on my 2023 Ford Bronco but the brake and turn signals do but dimmer than normal after installing smart diodes connected to each tail light wire? Small side marker lights illuminate indicating that there is voltage getting to the light. Do I need to install the regular Hy-Power diodes on each separate wire instead of using the smart diodes?

asked by: Jeff A

Helpful Expert Reply:

A 2023 Ford Bronco would only need to use smart diodes if it has variable voltage tail lights. Variable voltage tail lights use the same wire for the brake signal and running lights instead of the standard turn/brake wire setup. To determine if you have variable voltage tail lights you'll need to pull the tail light out to get to the wiring and test wires with a probe tester # PTW2993 in order to see if the same wire powers both the running lights and brakes.

If you do have variable voltage tail lights you'll need part # RM38FR (LED) or # RM26FR (Incandescent). If you don't have variable voltage tail lights you would need to use standard diodes like in part # RM-15267.

Once we know the correct diodes for your Bronco we can then troubleshoot any function loss and get your Bronco flat tow ready.