Setting Up Australian-Market 2010 Hyundai Santa Fe to Tow Trailer With Electric Brakes

Question:

Hello, I have purchased a second hand 2010 Hyundai Santa Fe Highlander which has a 7 pin flat connection at the tow bar. I have noticed that there is a blue wire going to pin 5 which should indicate there is a service brake. I cant see any electric brake contoller anywhere in the car and I dont appear to get any voltage between pin 5 and 3 when I apply the brake. What would this wire be controlling? I want to add an electric brake and permanent 12 v supply to pin 2 to power a fridge in my caravan. I appreciate your time in this matter.

asked by: Derek

Expert Reply:

In the US market, Hyundai does not pre-wire the Santa Fe for electric trailer brakes. From my research online, I found that an Australian 7-way flat trailer connector does use the blue wire in the # 5 position to carry trailer brake output voltage.

To actuate your brakes, you would need to install a brake controller. Your vehicle might be pre-wired, you would need to check with a local Hyundai dealer about that, there might be an adapter harness available that would make installation very simple. If your vehicle is not pre-wired, you would need to hardwire the brake controller, routing your own connections for the brake controller power supply, ground connection, output to the trailer connector and connection to the brake stoplight switch. I have linked you to a help article that outlines how to hardwire a brake controller.

The 7-way flat does not provide for a 12-volt accessory power connection. You might be able to use the # 2 pin for that purpose, but I do not know anything about the legality of doing so in Australia. You would run a 10 gauge wire from the positive battery terminal through a 40 amp inline circuit breaker back to the # 2 pin on your trailer connector. You might also consider a battery isolation solenoid like part # PK5231201 which will disable that 12-volt accessory circuit when the vehicle ignition is switched off. This would prevent the battery of the tow vehicle from being accidentally discharged.

expert reply by: Mike L