Installing an Electric Trailer Brake Controller from Scratch on a 2002 Toyota Tundra

Question:

Hi - I have a 2002 Tundra SR5 that came with a factory installed frame hitch and trailer wire harness. At the hitch there is a 4 Wire flat connector and harness that connects into a larger harness under the truck near the drivers side,aft, close to bumper/frame. Up front under the hood there is a 30 amp fuse and wire coming off the positive battery terminal. I want to install a brake controller and a 7-pin trailer wire connector. Questions I have for you: 1 is there a direct connect adapter harness for my vehicle configuration allowing controller plug-in without splicing, 2 is there a direct connect wiring harness to replace the 4-wire with a 7-wire connector aft or do I use your 4 - 7 adapter kit and run the additional wires needed. 3 what is the purpose of the existing 30 amp fuse in the existing harness at the battery positive terminal. Thank you for your help - I think the Prodigy sounds like the controller for me.

asked by: Dave R

Expert Reply:

I checked with the brake controller and wiring harness manufacturers we carry and they do not have a 7-Way wiring harness or brake controller harness for the 2002 Toyota Tundra. All of the parts they have listed start with the 2003 model year. In this case, you will need to install the 4 and 7 Way Installation Kit, # ETBC7, for the Tekonsha Prodigy P2 Brake Controller, # 90885.

Installation is not too difficult, especially if you have experience with automotive projects and electrical wiring. Your existing 4-Way will plug into the back of the ETBC7 leaving 4 wires that will need to be hard-wired. Using the included duplex cable, the black wire will attach to the positive battery terminal via a 40 amp circuit breaker. The blue wire will attach to the break controller blue wire. The white wire will attach to the truck frame, and the last wire can be connected to the reverse light wire behind one of the tail lights if needed.

On the brake controller, you will use the extra wire left over from the duplex cable. The white wire will need to attach to the negative battery terminal. The black wire will attach to the positive battery terminal via a 20- or 30-amp circuit breaker (see brake controller instructions for which size to use). The red wire will attach to the cold side of the brake switch. Use a circuit tester like # PTW2993 to find the wire on the brake switch that carries a signal ONLY when the brake pedal is pressed.

I have included a link to an FAQ article explaining how to install a brake controller from scratch and a video showing the installation of an ETBC7. The existing wiring harness probably requires the 30 amp fuse to allow the harness to work. Other trucks need additional fuses and/or relays for the wiring to be fully activated. This is probably the situation on your truck.

expert reply by: Michael H