How to Wire Back-Up and 12 Volt Light Wiring when Installing A 7-Way Connector on a 1999 Dodge Van

Question:

1999 Dodge B3500 Van: Where do I wire purple center wire for back-up lights on cargo trailer function, in van? How do I get aux power for interior lights in cargo trailer? Can I tap in to the hot lead for the trailer brakes? Thanks.

asked by: Bob H

Expert Reply:

Installation of a brake controller and 7-Way wiring connector on a 1999 Dodge Van is pretty straight forward. You will first need a working 4-Way connector. If you do not already have one the T-One wiring harness, # 118368, is the correct harness for your van.

You would then need a brake controller installation kit, # ETBC7. This kit includes the 7-Way trailer connector, wiring, circuit breakers and other hardware needed to complete a professional looking installation. We also have detailed instructions and an installation video to help you through the installation, see links.

The purple backup light wire should be extended and tapped into the reverse light circuit at the rear of your taillights. A circuit tester, # PTW2993 or similar, is needed to locate the backup circuit. You can normally look at the back of the taillight housing and determine which wires to test by the backup light location.

The auxiliary 12-volt power wire should not be attached to the lead for trailer brakes. This circuit should be run from the positive post of the vehicle battery, through a circuit breaker, to the number 4 connection point or black wire coming from the back of your 7-Way connector. This will provide 12-volt power for your cargo trailer interior lights. I attached a photo of the 7-Way vehicle and trailer side connector wiring configuration for you, see link.

Finally, if you do not have a brake controller, I would recommend the Prodigy P2 brake controller, # 90885, which is our best-selling brake controller and gets great reviews by our customers.