Using Separate Brake Lights and Turn Signals on Home Made Tear Drop Trailer

Question:

My 2004 Tacoma has separate amber turn signals. I am building a camper tear trailer that I want separate amber turn signals on the trailer also. The trailer needs a 12 volt positive constant to charge the deep cycle battery on the trailer. The trailer is small and will use an idler axle with no electric brakes. Can you recommend the wiring configuration using the oclock method facing the rear of the tow Tacoma for the connector. Also can you recommend the wire color and gauge for each, I understand that I may have a dedicated tow vehicle/ trailer set up . Is a converter recommended instead and just resign myself to a combination turn/brake/tail light assembly on the trailer?

asked by: Mark T

Helpful Expert Reply:

The best solution is to use a standard combined wiring harness on the 2004 Toyota Tacoma and then separate out the signals on the trailer side. That way your truck will still have a standard connector in case you need it in the future.

Since you need lights and 12 volt power I recommend going with a 7-Way which is very common. To add a 7-Way to your truck you will first install a 4-Way using # 118379. Then you will need 20 feet of wire # 12-1-1, and a 40 amp circuit breaker # PK54540. And you will need # 37185.

On the 37185, the 4-Way will plug into it and you will need to hardwire the remaining wires. White will ground to the truck frame, blue you will not need (for electric brakes) and purple is for reverse lights but if not needed you would stow it out of the way. The black wire will need to attach to the extra 12-1-1 wire, run it under the truck to the engine compartment, and then to the AUX post on the circuit breaker. Then from the BAT post run another length of wire to the positive battery terminal.

On the trailer side you can use 7-Way # H20042. But to separate out the combined turn and brake lights you will need to add converter # C56196. On this converter the input wires are green for combined right turn and brake and yellow for combined left turn and brake. The white wire is the ground. On the output side you will have a red wire that is just for brake lights, yellow for just left turn signal, and green for just right turn signal.

For additional wiring on the trailer you can use # DW04914-1. Both it and # 12-1-1 are sold by the foot.