Charles Patterson

Trying to convert a 2015 f-150 from a 4 pin connection to a 5 pin for surge brakes on a boat trailer.

jhanna

I believe all you have to do is add the reverse light wire. I don't think I'd tap off the stock reverse, rather run a new lead from the fuse block by the radiator.

If I were going to do this, I'd go ahead and run the other 2 wires for a full 7 pin jack.

jhanna

Another thought, from my understanding, some trucks have all wires present. If you look under your truck, you will see the wires from your existing 4 pin jack running back to a pair of male/female connector halfs. It's only about a foot or so back toward the front of the truck on the frame by the spare tire.

This harness from the front of the truck, may have only the wires fir the 4 pin, but I believe I've read were some trucks have all the wires for the 7 pin at the front side connector.

This would make your job much easier if all wires are there.

jhanna

This picture shows what you're looking for, in the red circle. Even though picture is not your year, it's still the same. That front side connector may gave all the wires you need.

jp360cj

Do you have a 7 way plug on the truck? if so, then you can just a an adapter for the 7 way to 5 way. If you don't, I would add the OEM 7 way plug, then run an adapter.

There are also 4 way to 5 way adapters that have an extra quick connect wire to run to the reverse lights. Typically, the only thing the reverse light circuit does is disengage the surge brakes for backing up. This may or may even be an issue for you. My dad's bass boat has surge brakes with a regular flat 4 and a manual disengage for the surge brake. The brakes have never been an issue backing into the water (downhill). On occasion, he will have a problem backing it into the garage (slight uphill), but usually he can just pull forward a bit to release the brakes and back up again.