Recommended Trailer Wiring for an Audi Q5 Compatible with a Bike Trailer

Question:

Hi Ive had a bike trailer fitted to an Audi Q5 but the brake lights dont work when the main lights are turned on. They work fine when no lights are turned on so Im thinking this must be a wiring problem when fitted?

asked by: Ben T

Expert Reply:

The issue is that your lights are pulling or drawing too much power for your trailer connection to work properly. This could be due to a short or a bad ground. I recommend checking your ground connection first to ensure you have a corrosion free bare metal to metal connection. Then check your wiring for a short using a circuit tester like # PTW2993.

If all that checks out, then I recommend using the Tekonsha ZCI Circuit Protected Vehicle Wiring Harness with Install Kit # 119250KIT which is a powered converter that is confirmed to fit an Audi Q5 and will allow your bike trailer to work properly when the headlights are on. This will require routing the power wire, so I've attached an article to assist.

expert reply by: Jason S