Will the Custom Wiring Harnesses for a 2020 Toyota Sienna Work w/out Being Wired to the Battery?
Updated 09/30/2025 | Published 09/27/2025
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Question:
For my 2020 Toyota Sienna LTD AWD, will the T-connector harnesses such as the Curt C56261, the Tekonsha 118648, and the Hopkins HM43494 draw enough power without connecting the provided power lead to the vehicle battery for an LED light bar on a bike rack, which only draws 1 amp in brake light mode?
asked by: David Y
Expert Reply:
Hey David. The Curt item # C56261, the Hopkins item # HM43494, and the Tekonsha item # 118648 require being wired to the battery to work. They won't even function let alone supply power if they're not wired directly to the battery in your 2020 Toyota Sienna. The consistent power supply provided directly from the battery is what powers the control modules that send the signals from your Sienna's tail lights to the 4-way connector.
Out of those three options, I recommend going with the Tekonsha item # 118648 because their control module is more reliable than the other brands. This harness is custom fit for the standard model of the 2020 Toyota Sienna. It will not fit the SE. The connectors will plug into your van's wiring harness, which is located behind the driver's-side and passenger's-side tail lights.
What kind of bike rack do you have?
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