7 and 4 pin light hook up

My 15 has a 7 pin harness from the factory which is great for a camper but not so great for my boat. Can I take the 7/4 pin from a third gen and wire it to work? When I search all I see is the adapter kit(that o don’t want bc it can be stolen).

 

I’m sure it could be done.
And probably wouldn’t be that hard.
I personally run the 7-4 adapter, if I think it’s going to get stolen, I leave it in the truck.

You can either tap in a 4/pin off the existing 7-pin wiring.
Or if you want, you could cut the whole 7/pin off and do a 3rd Gen.
That just sounds like a lot of work, compared to tossing an adapter in truck?

Anyways, the current 7/pin cover on your truck should have the wiring diagram right on it.

 

I'm not sure I understand. Why would an adapter be stolen? Use it when the trailer is hitched, stow it in a cubby when it isn't. They're 10 dollars on Amazon, not a huge issue if one walks off.

 

Yes, you could, easily. The existing harness that plugs into the back of the '15 receptacle should match a gen 3 receptacle. However a plug-in adapter would be even simpler.

 

Wire the boat trailer plug to 7pin?

 

The 2nd gen schematic




Sure doesnt look like the 3rd gen per the schematic, but no guarantees from me one way or the other...

 

I suppose you could make it work.
But not with out splicing wires. It wouldn’t be plug n’ play.
You’d also need the pin layout for the 3rd Gen plug to make it easier.
Or pin and paper it with a Volt/Ohm meter.

 

an electrical schematic in no way represents what the physical layout of the wiring and connector looks like. Best bet is to compare the connector between the two, and determine if they will mate up. If not, I’d suggest the adapter as already mentioned, otherwise you can cut the trailer socket and reconnect the 3rd gen pigtail to it.

 

Go to Walmart, get an adapter, call it a day

 

I also make no guarantee, but Curt Mfg shows that Toyota started using the USCAR 7 way socket back in 2007. My 2019 has the USCAR connection on both the rear and front side of the connector. I may be incorrect in assuming that the 2015 is the same.

(Cut & paste)

What is a USCAR 7-way socket?
A USCAR 7-way socket is a standardized automotive electrical socket that provides a connection point for trailer wiring.

The socket is used across several different makes and models, allowing for easier access to parts for both manufacturers and vehicle owners.

https://www.curtmfg.com/towing-electrical/original-equipment-replacement-connectors/learn-more

The plug-in adapter is still the simplest way.

 

Agreed, that is the only way to know for sure.
That said, both schematics list it as T12, but the Pin #s/function are not the same 2nd gen to 3rd gen per the schematic. Hard for me to believe they would change the pin numbering on the connector....
Know what the pin #s/functions of the 3rd gen are, but I dont have a connector pin-out for the 2nd gen.

3rd gen

 

Yes, from what I’ve seen

1. Connectors are different.
2. Pin layout is the same.
3. The pin numbers on the diagrams are different.

You be better off wiring the 2015 up as 2016+
That way what ever fits in the 2016 harness should work correctly?

 

I’ll see if I can pull one up, but a 7 pin round has standard pins that are used and then mate up to the trailer. What’s more important is the EB1 and BE1 connectors. If they are not the same your only choice is to splice or use an adapter, or take the pins out of the connectors and repin to match. That hardly seems worth anyone’s time. When I busted up my 7 pin, I cut the wires at the harness pigtail and soldered on a Hopkins 7pin/5pin combo plug. Total cost was about $15 and maybe an hour of time.

 

This is the trailer wiring standard for a 7 pin. Don’t pay attention to the colors, they are for standard wiring at the trailer end.

 

2nd gen T12 pinout, T12 Trailer Socket 82824–3405




2nd gen BE1 connector

 

2nd Gen looks like it uses 1 connector into T12.

3rd Gen come from 3 different connectors into
T12.

 

The whole reason I’m considering this is ease of use. I have a boat, a small camper, and a 5x10 trailer. Went to pick up my dads big bass boat today and it was a 4 pin not a 7 pin. Guess who didn’t bring their adapter and had to buy on from a boat shop? Me!
To me it is a big issue if I’m fishing at night and someone walks off with it, no lights. I have another ding ding moment and forgot it,no lights.

 

So essentially I need to hook into 1,3,5,6 for what I’m needing?

 

If you’re determined to make it work.
The easiest way would be to add a 4/pin to the existing harness.
I’d pass on retrofitting a 3rd Gen plug.

 

Gotta ask what part of Tn are you from. We might be neighbors