Replacing 6-Pin Square Trailer Connector on Jayco Pop-Up Camper With a 4-Way Flat

Question:

Thank you for your advice on converting my Jayco motorhome from a 6-way square to a 4-way flat. I have two wires in question. The black is aux and you recommended taping it and not using it. Is that wire for a purpose like aux battery and can I hot wire it to something like tail lights? 2 blue wire on trailer for the electric brakes. Should that be wired to the brown tail lights on 4 pin flat? Thanks

asked by: Gary L

Expert Reply:

It sounds like you are replacing your older 6-pole wiring harness on your Jayco popup camper to a 4-flat connector like # HM48110. When you do this, you will have the black auxiliary wire and the blue brake wire remaining. You will no longer be able to use those functions, so those wires can just be taped up and stowed out of the way. The 4-Way trailer end functions are brown for running light circuit, white is the ground, green is right turn/stop, and yellow is left turn/stop.

In regards to your first question, you can splice the black wire into the running light circuit, which will provide a maintenance charge to the battery when the running lights are on. However, this will keep the tail light on if the battery has a charge, so a one-way diode like # RM-790, would be needed on that wire. The downside to doing this is that if anything else is running off that battery and it overloads the tail light circuit, then it could short the the tail light circuit or blow a fuse.

In answer to your second question, the blue wire on your 6-way plug is for the trailer brakes and will not be used on a 4-flat connector.

It will be helpful to have a circuit tester, # PTW2993, some butt connectors, # DW05745-5, and some dielectric grease, # 11755, on hand for this project.