How to Determine If My RV Has Separate or Combined Lighting for Installation of Roadmaster Diodes
Updated 07/30/2021 | Published 07/28/2021 >
Question:
Could you clarify use of the 4 diode system on a TOAD with separate tail, turn, and brake light assemblies? Specifically with only 4 diodes, you can only splice into TOAD tail light and brake light wiring. You are suggesting in your explanation that the brake light also acts as a turn signal only one of the two filaments in that bulb when hooked to the towing motorhome. How can you determine via the motorhome wiring plug that this is indeed the case??
asked by: Andy H
Expert Reply:
I do believe you're asking how to determine whether or not your RV has a combined or separate lighting system. If the motorhome’s trailer plug energizes the same pins on the 4 way connector for both brake lights and turn signals, then a 3-to-2 converter is already installed and the motorhome should be treated as combined lighting when installing the Roadmaster # RM-154.
Product Page this Question was Asked From
Roadmaster 4-Diode Universal Wiring Kit for Towed Vehicles - 4-Way Flat Connectors
- Flat Tow Wiring Harness
- Splices into Vehicle Wiring
- Diode Kit
- Universal Fit
- 4 Flat
- Roadmaster
more information >
Featured Help Information
Instructions
Continue Researching
- Shop: Vehicle Tow Bar Wiring
- Shop: Vehicle Tow Bar Brake System
- Search Results: rm 88400
- Shop: Roadmaster Brake-Lite Relay Kit for Towed Vehicles
- Shop: Roadmaster 4-Diode Universal Wiring Kit for Towed Vehicles - 4-Way Flat Connectors
- Search Results: rm 154
- Search Results: aventa
- Search Results: blue ox bx7335
- Search Results: safety cables
- Search Results: vehicle lights
- Search Results: return~police
- Shop: Curt Single Hook, Coiled Safety Cables with S-Hooks - 42" Long - 7,500 lbs - Qty 2
- Shop: Demco 4-Diode Universal Tail Light Wiring Kit for Towed Vehicles - 4-Way Flat Connector
- Q&A: Wiring a Motor Home with Converterd Wiring to Tow a Vehicle with Separate Turn and Brake Signals
- Video: DIY Install: Roadmaster 4-Diode Universal Wiring Kit for Towed Vehicles on your 2010 Ford Flex
- Video: Roadmaster Brake-Lite Relay Kit Comprehensive Review
- Video: Comprehensive Review: Roadmaster Brake-Lite Relay Kit for Towed Vehicles
- Video: Installation: Roadmaster Brake-Lite Relay Kit for Towed Vehicles on a 2008 Ford Edge
- Shop: Blue Ox Avail Non-Binding Tow Bar - RV Mount - 2" Hitch - 10,000 lbs
- Q&A: All Parts Needed to Flat Tow 2014 Ford Flex
- Video: Installation Guide for the Roadmaster Universal Hy-Power Diode Wiring Kit on a 2019 Ford Flex
- Shop: Blue Ox Alpha Non-Binding Tow Bar - RV Mount - 2" Hitch - 8,500 lbs
- Video: How to Install the Roadmaster Brake-Lite Relay Kit for Towed Vehicles on a 2011 Ford Edge
- Shop: Roadmaster Bulb and Socket Tail Light Wiring Kit for Towed Vehicles - Incandescent
- Video: How to Install: Roadmaster Brake-Lite Relay Kit for Towed Vehicles on your 2018 Ford Expedition
- Q&A: Will Curt RVibrake Shadow 2 Fit 2026 Ford Maverick Hybrid
- Q&A: Blue Ox Flat Tow Setup for 2026 Ford Maverick Hybrid
- Q&A: Complete Setup for Flat Towing 2026 Chevrolet Colorado
- Q&A: Best Flat Tow Setup for 2026 Ford Maverick Hybrid
- Q&A: Recommended Flat Towing Parts for a 2022 Ford Maverick


