Recommended Wiring Harness for a 2017 Audi Q5
Updated 12/22/2025 | Published 10/06/2024
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Question:
I have a Curt 56404 wiring harness in my 2017 Audi Q5. It is a two bulb/ 3 wire system. I want to replace the converter as I believe it is malfunctioning. There are 5 wires going into and out of the condenser brown, green and yellow, white ground and black positive. All of the replacement converters I have seen have an additional red wire for brakes. Is there any replacement converter with just the brown, yellow and green without the red? Or can I get a converter with the red wire and leave the red unconnected? Thank you.
asked by: Chip G
Expert Reply:
Chip, all of the wiring harnesses we have like the Curt T-Connector # C56404 is going to include that red wire for brakes. The rest of the wiring goes:
-Green for right turn,
-Yellow for left turn,
&
-Brown for taillights.
If you don't plan on using a brake controller, then you can leave the red wire disconnected.
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Jameson C.
12/22/2025
Hey Chip, how did things go with the Curt wiring harness on your Audi Q5 after leaving the red brake wire disconnected? It’d be great to hear if that setup solved the issue with your converter. Your update could make it easier for the next person with the same wiring question.