Do You Need a Brake Light Relay for a 2018 F-150 with Blue Ox EZ Light Wiring?
Updated 03/17/2026 | Published 03/16/2026
Question:
Do I still need a brake light relay with this harness on a 2018 F150 Lariat?
asked by: William H
Expert Reply:
Hi William,
I checked directly with Blue Ox, and with the EZ Light kit part # BLU92HR on your 2018 F150 Lariat, you will not need a brake light relay. That harness is designed to work with your truck’s wiring as is, so you can keep the install clean and straightforward without adding that extra component.
At that point, the main thing you’ll need to complete your setup is the coiled electrical cable like part # BX88206 to connect everything between the motorhome and the truck. You will need to cut off the 4 flat connector on the harness and rewire those wires into the 6 pin round that comes with the BX88206.
I totally understand wanting to make sure you get this right the first time and don’t have to go back into the wiring later.Which braking system are you using on the Lariat, and what trip or campground are you getting this set up for next?
William H.
3/17/2026
Also, the page on th eBLU92HR specifically mentions that you might need a brake light relay. You might want to fix that.
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on Flat Tow Wiring Harness
William H.
3/17/2026
Not decided on a braking system yet. I do know that I'll want a charge wire to the 6-way connector. Do you have a diagram showing which wires from the EZ Light kit part # BLU92HR 4 wire plug go to which connections on the 6 pin?