Parts Needed to Re-Wire Tandem Axle Gooseneck Trailer for 7-Way Type Operation

Question:

I have a 25 ton tandem axel dual wheel with electric breaks. Its have 5 wires black, brown, blue, green, and yellow. I need to wire it to a 7 pin. Every thread I have seen had a white wire. I do not have one so how should I wire it. Thank you

asked by: Brad

Expert Reply:

We can help you re-wire your tandem axle gooseneck trailer to have a 7-way plug to match your tow vehicle. Have a look at the linked article on trailer wiring. Typically a white wire is used for ground.

There are several ways a 7-way can be wired so you will want to ensure that each circuit on the vehicle socket is correctly matched to the appropriate circuit wiring on the trailer. Testing the trailer light functions with a spare 12V battery can make this identification easier.

You can use a handy item like the Epicord 7-Way Molded Trailer Plug with Junction Box # 277-000141 to make the wiring connections from each trailer circuit. You will need ring terminals like # 44-5310A on each trailer wire to make those connections inside the junction box.

A 7-way type trailer connector has the circuits to carry stop, turn and tail light signals plus 12V trailer auxiliary power, reverse lights and trailer brake signals. As mentioned above these functions can be assigned to different pins on the 7-way so matching functions (not wire colors) is important.

expert reply by: Adam R