Trailer Brake Lights Do Not Work When Connected have a 96 ranger with seprate turn and brake

Question:

My trailer is a 96 jayco popup that has a 6 wire plug and p/u has a 7 plug flat but cant get brake lights to work

asked by: Robert

Expert Reply:

Whenever any type of adapter like # PK12716 is used to mate different types of connectors on the vehicle and trailer, connection problems can develop because of all the extra contact points. The best way to go is to install a new connector on the trailer that directly matches that on the tow vehicle so that you can avoid using an adapter.

This is easily done by using a junction box like # 38656 and a new 7-way plug like # H20044. All you need to do is verify the function on each trailer wire and then match them up to the wire functions for the Hopkins plug. You can simply apply 12V power to the wires on the trailer to see what function is active; then you'll know how to splice the trailer wires to the plug wires so that the functions match. Wire color alone cannot be relied on. Test to confirm and match functions. The Hopkins harness functions are shown on the linked photo. You can use ring terminals # DW05705-1 (six in total) and # DW05737-1 (eight in total).

You can also test your Ranger's 7-way with a tester like # PTW2993. This will let you know whether it is sending out the correct signals to your trailer. The linked video illustrates how to do this testing while a helper activates the truck's functions.