Parts Needed to Install a Trailer Brake Controller on a 2004 Land Rover Discovery II

Question:

I was hoping you could help me. I am looking to fit a trailer braking system on my Land Rover and not sure which one I need. I have a land rover 7 way wiring harness already on the vehicles. I believe it is a european harness as it is 7 pins From doing a small amount of reading I hear that the P-3 is a good choice. Am I right in thinking that this will need to be wired in or is there a plug already on the car for it?

asked by: George C

Expert Reply:

It sounds like you have a 7-Way blade style trailer connector which will look like # 37185. If you do have a European 7-Way, it will have a different design and pin functions. Use a circuit tester like # PTW2979 if needed to test the pins to determine what functions they have. Then compare those to what we list is the FAQ I linked to determine if you have a common North American type of connector or a European connector.

If you do have a European trailer connector I do recommend switching that to a 7-Way blade style by using the # ETBC7. But if you have a regular 7-Way blade style already then you will just need the brake controller itself and an installation kit like # 5506 for 6 to 8 brake assemblies.

The P3, # 90195, is a great brake controller. It has a lot of useful features such as easy to understand diagnostics and it can be used with electric brakes or electric over hydraulic braking systems. There is no plug and play harness available for installing the controller so it will need to be hardwired using either the ETBC7, 5505, or 5506 wiring kits depending on the connector that is on the vehicle.

I have included a link to an FAQ article that should help. If you do just need 5505 or 5506 then what you will do is wiring in the controller as described in the FAQ for the white, black, and red wires but the blue wire will be a little different. You will use the wiring kit to attach to the blue wire on the controller, route it under the vehicle and to the correct pin on the back of the 7-Way by either replacing the wire that is there or cutting it and wiring the routed wire to end that leads to the brake controller.

On the back of the 7-Way blade style the brake output location is in the 7:00 position.