Rewire trailer from Flat 5 to 7 Pin

[David D]

I'm sure this is fairly straight forward, but I am considering rewiring the connector on my trailer from a flat 5 connector to the round 7 pin that's on my truck. My goal is primarily to have hot power at the trailer so I can install LED landing strip lights that activate with an electronic bilge switch.

Originally I was just going to tap into the existing trailer lights, but that would require that my parking lights be on in my truck. And if I'm gonna do this project, I may as well do it all right.

Anyone changed the wiring? When I look online, it seems every diagram shows the 12v hot in a different location (sometimes position 4, sometimes 7)??

 

[JetPowered]

Pin 4 is 12v always. Pin 7 is 12v reverse only. I'd wire off of running lights pin 3.

 

[KXCam22]

Here is a wiring diagram I made for the 2008 MFI. Cam.

 

[Bill D]

I did this about a month ago so I could add landing strip lights and @KXCam22 's diagram was spot on.

 

[Bruce]

I swapped the 5 pin for a 7 in 2013. I love not needing the adapter. It was perhaps a 30 minute project. The 7 pin adapter came with a small document labeling the pins. It may have even had the color codes. I used a drill battery to test each wire before connecting it to the 7 pin connector.

 

[Wayloncle]

I swapped mine as well, much easier than using the adapter. My outlet cover on my truck has the diagram on it, and the plug came with one, very simple swap.

 

[sysinu]

Upgrade your brakes to electric instead of hydraulic while you're at it ;-).

That said, pep boys and camper world seem to have the best kits for changing this out. Just be careful about how much cable you chop off. When you put the 7-pin connector on, it uses about 2.5" of cable, and you're losing about 1" of cable when you chop off the 4/5-pin connector. Also be sure to put some heat shrink tubing on before you wire up your 7-pin adaptor (learned that the hard way).

I had to create a 7-pin 1' extension cable (I ended up making it 18" long), though I'm sure I could buy one online, because I decided to add hitch attached mud flaps to my rig. Be very mindful of your cable length!

 

[buckbuck]

Wow Cam. Nice drawing. I stuck that in my boating folder for the future.

 

[David D]

I was going to thank you all by name, but so many of you responded that I'll just say say thanks to all of you. I think I'll use the 12v always on pin since I'm adding a water sensing switch. And thanks for the reminder about cable length too.

I hope to remember to take pictures -- cause if I don't, it didn't happen.

Thanks guys.