How To Wire Separate Turn Signals And Backup Lights On A Trailer With a 4-Flat Connector

Question:

Hi Ive got a 2005 Chevy Tahoe and using an adapter to connect a flat 4-prong trailer plug to the round 7-terminal receptacle. My trailer has separate amber turn signals and white backup lights none of which Im currently using because Im limited w/ the current wiring scheme. Id like to be able to use them by adding the appropriate wires and connections on the trailer, but am a bit confused how to wire the truck end. I think I wire the backup lights to the center terminal because thats what the little diagram on the receptacle cover says. But Im not sure about how to separate the turn signals because theyre notated on the diagram as the same terminals LandR as the brake lights. Or would I use the electric brakes terminal even though the trailer doesnt have them for a separate brake light wire? But if I do that, would the turn signals come on too when the brake pedal was pressed? Thanks for your help.

asked by: Jeff M

Expert Reply:

To wire your trailer for separate turn signals you will need to use the Pollak 7-Pole Trailer Connector, part # PK12706, and the Tow Ready Vehicle to Vehicle Taillight Converter, part # 118158. You will replace the 4-flat on your trailer with the Pollak 7-Way connector.

The wiring on your 2005 Chevrolet Tahoe with the 7-way connector will stay as the factory wiring. It will not need to be changed.

I am including a picture of the 7-way trailer connector that will show the function of each pin. Looking at the inside of the Pollak 7-way trailer connector you will run a wire for the reverse lights from the center pin to the backup lights on your trailer. You will have to split the wire at the rear of the trailer and run one wire to each backup light.

The (4) pin at the 1:00 position is for 12v power and will not be used. The (6) pin at the 3:00 position is for right turn and a wire will run from there to the green wire on the input side of the taillight converter. The (2) pin at the 5:00 position is for brake controller and will not be used. The (1) pin at the 7:00 position is the ground and will need to be grounded to a good, clean ground on the trailer frame. The (5) pin at the 9:00 position is for left turn and a wire will run from there to the yellow wire on the input side of the taillight converter. The (3) pin at the 11:00 position is for taillights and a wire will run from there and split to the right and left stop/taillights on the rear of the trailer.

The only thing left is to connect the remaining wires on the taillight converter. The remaining white wire on the input side will be grounded to the trailer frame. The green wire on the output side will need to be connected to the right turn signal at the rear of the trailer. The yellow wire on the output side will need to be connected to the left turn signal at the rear of the trailer. The red wire on the output side will need to run to the rear of the vehicle and split to the stop/taillights on each side of the trailer.

This will give you separate turn signals and backup lights on your trailer when you plug the 7-way on your trailer into the 7-way on your vehicle.