Connecting separate reverse trailer lights using 5-pole wiring harness
Question:
Hi, I have a 2005 Scion xA equipped with a 4-pole connector. Im trying to replace the trailer lights on a small, single-rail motorcycle trailer - 2 lights on each side, each having 4 wires (white - ground, yellow - reverse, black - tail, red - brake/turn). What I understand so far is that I will need a 4-pole to 5-pole adapter for the extra blue wire to run the reverse lights on the trailer once I spice into the reverse light circuit of the tow vehicle. My question is, once I wire the running/brake/turn lights and all I have is the blue auxiliary wire, how do I connect that to the two separate reverse light wires the yellow wire on each trailer light? Thank you!
asked by: Cip
Expert Reply:
You are definitely on the right track. Start off by installing the Tow Ready 4 Pole to 5 Pole Trailer Wiring Adapter # 20036 on your tow vehicle with the Blue wire running to your reverse light signal.
Once that is done I then recommend cutting off the 4-Way Flat connector on your trailer side and installing the Hopkins Endurance 5-Way Flat Trailer Connector # HM47910 using Butt Connectors # DW05744-10 to secure your connections (wires on the 5-Way are labeled). You can either run to separate wires right from this connector or run one length of 16 Gauge Wire # 16-1-1 back to one of the lights.
Regardless of which you do you will then want to use a slightly larger butt connector, part # DW05745-5, and connect the one wire from the 5-Way Flat on one end. You will then insert 2 of the 16 Gauge Wires # 16-1-1 into the other end and then run either wire to either Yellow wire on your lights.
I have attached a sample installation video of the Hopkins # HM47910 being installed. It isn't quite the same installation but it should get you most of the way.

Question:
Hi, Im using the 4 pole to 5 pole adapter to hook up a small, single-rail collapsible motorcycle trailer that has wires for reverse lights to a 2005 Scion xA. Im trying to splice the blue wire on the adapter to the reverse light wire on the vehicle. In searching the web, I found out the reverse light is a red/black wire I will also be using a circuit tester to make sure this is correct, but my problem is that there are two red/black wires, one for each reverse light on the back of the vehicle. Where do I splice the adapters blue wire? Do I need to go further down the wire harness remove panels and towards the front of the vehicle, to find a single reverse light wire that eventually splits into two? Thanks for the help!
asked by: Cip
Expert Reply:
If you test the red/black wires and both of them carry the reverse light signal then you can actually tap into either one. Even though they split off to separate sides of your Scion they both act the same so you just need to tap into one of them.

Products Referenced in This Question
Deka Heat Shrink Butt Connector - 16-14 Gauge - Nylon Insulation - Blue - Qty 10
- Wiring
- Wire Connectors
- Butt Connectors
- 16-14 Gauge
- Deka
more information >
Deka Heat Shrink Butt Connector - 12-10 Gauge - Nylon Insulation - Yellow - Qty 5
- Wiring
- Wire Connectors
- Butt Connectors
- 12-10 Gauge
- Deka
more information >
Hopkins Endurance 5-Way Flat Trailer Connector - Trailer End - Ergonomic Design
- Trailer Wiring
- Trailer Connectors
- Trailer End Connector
- 0 - 5 Feet Long
- Plug and Lead
- 5 Flat
- Hopkins
more information >
Product Page this Question was Asked From
Tow Ready 4 Pole to 5 Pole Trailer Wiring Adapter
- Trailer Wiring
- Wiring Adapters
- Single-Function Adapter
- 0 - 5 Feet Long
- 4 Flat
- Plug and Lead
- 5 Flat
- Tow Ready
more information >
Featured Help Information
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