Trailer Wiring 4 Way Flat to 5 Way Round

[MJR63]

I have a new 2016 Toyota Highlander V6 with the factory hitch and wiring harness.  The factory harness has a 4 way flat plug and my 2011 Boatmate dual axel trailer with disc brakes has a round 5 way.  I believe the 5th wire on my Boatmate trailer is used for the reverse lockup so you cannot backup the trailer without the back up wire connected.  Is there a 4 way flat to 5 way round plug adapter that can do this without any additional wiring?  Any suggestions would be appreciated!

Thanks

Mark

Edited June 18, 2017 by MJR63

[BillM22]

Check this place, I have found a lot of trailer parts here. 

http://www.easternmarine.com/Boat-Trailer-Parts/

 

 

[MJR63]

I found this on eTrailer and think it may work....

https://www.etrailer.com/Wiring/Hopkins/37175.html

[oldjeep]

I'd see if you can get factory 7 wire connector for your truck so you don't have to cobble up the wiring in a brand new truck.  Should have been an option.

As for the trailer, not sure what a round 5 wire is, suspect you mean 7 as that is standard.

Edited June 18, 2017 by oldjeep

[MJR63]

42 minutes ago, oldjeep said:

I'd see if you can get factory 7 wire connector for your truck so you don't have to cobble up the wiring in a brand new truck.  Should have been an option.

As for the trailer, not sure what a round 5 wire is, suspect you mean 7 as that is standard.

Yes, you are correct I have a 7 pin connector with 5 active circuits in the plug.  Unfortunately the 7 pin connector is not an option on the Toyota Highlander V6 so it looks like I'm going to have to go with this adapter and hook into the reverse lights for the trailer backup lockout...

https://www.etrailer.com/p-37185.htm

Thanks!

 

Edited June 18, 2017 by MJR63

[MadMan]

20 minutes ago, MJR63 said:

Yes, you are correct I have a 7 pin connector with 5 active circuits in the plug.  Unfortunately the 7 pin connector is not an option on the Toyota Highlander V6 so it looks like I'm going to have to go with this adapter and hook into the reverse lights for the trailer backup lockout...

https://www.etrailer.com/p-37185.htm

Thanks!

 

If you use that adapter, you still have to convert from 7pin round to 5 pin flat.  Why not just use this:

 

https://www.etrailer.com/Wiring/Tow-Ready/20036.html

 

[MJR63]

6 minutes ago, MadMan said:

If you use that adapter, you still have to convert from 7pin round to 5 pin flat.  Why not just use this:

 

https://www.etrailer.com/Wiring/Tow-Ready/20036.html

 

Thanks but my trailer has a 7 pin round and my car has a 4 pin flat so if I used this option I would still need a 7 pin round to 5 pin flat adapter....

[RTS]

Buy a flat 5 harness.  Cut your flat 4 off the vehicle and rewire the 5 into it, splicing a wire into your reverse light wire in taillight assembly.  Very easy job to do.  I did it on my Sequoia and it took about 30 minutes and a couple beers.

But no...you gotta get the reverse light signal from somewhere if you want everything to work correctly.

[jrvs23]

Go to etrailer and ask them which wire harness you need. You should be able to get one that simply plugs into the factory pin connection inside the back of  the highlander. As long as the factory connection is pre-wired to allow it. I had to replace my 4 flat when it corroded out and was super simple plug and go.

[ahopkins22LSV]

Guys, he said he has the round pin on the trailer already. He said 5 pin round. Probably just mistaked that as the 7 pin. I believe he has a he correct harness picked out. 

[MJR63]

Looks like this is the eTrailer harness that I need to convert my 4 pin flat to my 7 pin round:

https://www.etrailer.com/p-37185.html

Calling them tomorrow to confirm. 

Thx!

[patywatkins]

I'm having the same issue. I need to replace the factory 4 way flat to a 7 way round on my 2016 Toyota highlander. I purchased the 7 way recommended by e-trailer.com but have not yet installed. has anyone out there actually done this replacement and can you comment on the results?

[Nitrousbird]

Though this is an old thread, the answer should really be it doesn't matter as a 2011 Vride is over the max tow capacity of a Highlander.

[Smitdog266]

On a semi-related note... The wiring harness on my 2005 Boatmate trailer is toast, so am going to replace everything.

My question is what is the purpose for having the trailer brakes lockup when going in reverse unless you have the harness plugged in? I can move the boat and trailer in reverse by hand when the boat/trailer are standalone, on the tongue jack wheel and not connected to anything. But with my wiring screwed up, when the trailer is on the ball of my hitch, I can't back up without the brakes locking up.

Thanks!

[oldjeep]

1 minute ago, Smitdog266 said:

On a semi-related note... The wiring harness on my 2005 Boatmate trailer is toast, so am going to replace everything.

My question is what is the purpose for having the trailer brakes lockup when going in reverse unless you have the harness plugged in? I can move the boat and trailer in reverse by hand when the boat/trailer are standalone, on the tongue jack wheel and not connected to anything. But with my wiring screwed up, when the trailer is on the ball of my hitch, I can't back up without the brakes locking up.

Thanks!

It is a surge brake.  The pressure of the coupler pushing towards the trailer is what actuates the brakes.  The reverse lockout is a solenoid that keeps the coupler from sliding towards the trailer.