Is there a 4-Flat to 5-Round Adapter?
Updated 09/26/2025 | Published 04/20/2025
Question:
I have a 2022 Toyota Highlander with a factory hitch and the factory flat 4 pin connector. My boat trailer has a round 5 pin connector, no trailer brakes. Is there an adaptor available so I do not have to rewire anything. Or what are my options?
asked by: Ned M
Expert Reply:
Hey Ned there's not an adapter that will let you connect the 4-way connector to a 5-pin round connector like item # PK11501. What you'll need to do is cut that 5-pin off and install the Hopkins Endurance 4-Way Flat Trailer Connector - Trailer End item # HM48110.
If it was wired correctly the 5-pin should be have the 12 o'clock pin for the tail lights (brown wire) the 2 o'clock pin is the aux circuit (red), the 5 o'clock pin is the right turn/brakes (green) , the 7 o'clock pin is the left turn/brakes (yellow) and the 10 o'clock pin is the ground (white wire).
You won't need the 2 o'clock pin aux circuit (red).
Product Page this Question was Asked From
Pollak 5-Pole, Round Pin Trailer Wiring Connector - Chrome - Trailer End
- Trailer Wiring
- Trailer Connectors
- Trailer End Connector
- 5 Round
- Plug Only
- Pollak
more information >
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Jerred H.
9/26/2025
Hey Ned, did you have a chance to install the Hopkins Endurance 4-Way Flat Trailer Connector? I'm curious to know if it worked out for your boat trailer setup, as it could help others facing a similar situation.