4 versus 7-pin connectors

[Debbie in Florida]

Hi All --- many of you have been responding to my technical (and non-technical) questions about TVs. I am planning to buy a 16 or 17 foot Casita but am first going to get the tow vehicle. My focus is now on a Toyota Hylander, new, so I can get the factory installed tow package and limit searching for just the right used vehicle with low milage. I will be traveling solo so reliability is especially important to me.

So, I am down to looking at the Highlander tow package and asked about how many pins the connector has since I have been told to get a 7-pin connector. The dealer researched the issue for me and advised that the Toyota only has a 4-pin --- but that is enough. His explanation follows. Please give me your advice. Thanks so much in advance.

From the dealer:

I spoke to one of our service writers and he got me some details on how the highlander equipped with the 3.5L v6 model is able to tow 5,000 lbs

You can find it on Toyota’s website here ( https://www.toyota.com/highlander/fe...6948/6950/6954) under the weights and capacity tab.

It states the following:
Heavy-duty radiator with engine oil cooler, 200-watt fan coupling, supplemental transmission oil cooler and 150-amp alternator


As for the hitch and wiring, I have found out that the wiring harness that is installed with the hitch is all factory Toyota parts. The wiring harness hooks up to an input in the front for the vehicle for power. It is also a 4 pin connector. The difference between the 4 pin and 7 pin connectors isn’t much. The 4 pin is to connect break lights, turn signals, emergency lights. The 7 pin connector is the same but adds electrical input for a trailer break, which isn’t available on the Highlander and is really only used for very heavy trailer loads.

Also the 4 pin connector should work just fine for you because that connection has nothing to do with powering the interior of the travel trailer. The 4 pin and 7 pin connectors are only used for the indicator lights outside of the vehicle.

[Gompka]

Your dealer either has no idea what he is talking about, or he is lying to you just to encourage you to purchase the vehicle. Without the 7 pin connector you won't have trailer brakes, reverse lights, and your tow vehicle won't recharge your trailer.

Trailer brakes are good to have on any trailer regardless of weight, there are 4 pin to 7 pin adapters, the extra 3 wires would have to be ran separately and a brake controller would have to be installed. Many people will tell you that you don't need trailer brakes, but when you are trying to stop an extra 2000-3000lbs in a hurry you will wish you had them.

[Jon in AZ]

Originally Posted by Debbie in Florida

...The 7 pin connector is the same but adds electrical input for a trailer break [sic], which isn’t available on the Highlander and is really only used for very heavy trailer loads...

Hmmm... "very heavy trailer loads." I'd be willing to bet if you read the owner's manual for a Highlander it specifies trailers brakes with any trailer over 1000 pounds. That's what my Pilot says and is typical of vehicles in that class. Very heavy trailer??

In addition, pretty much any place you go in North America requires brakes over 3000 pounds, which includes most 17' trailers and some 16' trailers, and a number of states and provinces have even lower thresholds (1500 pounds in CA and 1000 pounds in NY, for example).

Toyota is being disingenuous here. You need trailer brakes and 7-pin wiring for almost any trailer bigger than a small utility trailer carrying a lawn mower, but they refuse to pre-wire the vehicle with the required brake line.

Honda provides the brake line and a port to easily connect a brake controller under the dash on the Pilot. The connector on the bumper is a dealer-installed accessory so you can choose between 4-pin and 7-pin, but both are simple plug-ins. Just sayin'...

Actually, any reputable shop should be able to upgrade the Highlander's wiring to 7-pin. Just don't expect any help or encouragement from Toyota.

Once you've done that, the Highlander is a competent and reliable tow vehicle.

[CarlD]

When I purchased my 2007 Highlander I ordered it with the trailer package, which included the larger alternator, cooler etc. However it did not include the connector for the trailer. I was told they do that because Toyota does not know what type of connector you will need. I added a 4 pin connector and had to purchase a converter to combine the turn signals with the brake lights, something the trailer lights require. The 7 pin connector incorporates a circuit for electric brakes and also a dedicated power feed. The dedicated power feed enables charging the trailer battery from the tow vehicle while driving and to keep things running in the trailer such as a compressor refrigerator. The wire size for the power feed is important. Larger wire means less voltage drop at the trailer.

1. If these things are important to you then a 7 pin is in order.
2. Be sure to ask Toyota if the connector is included with the towing package.
3. You can probably find a third party to install a 7 pin connector.

Hope this helps

[ststefan]

I have noticed that the difference between dealerships can be amazing. Some only want it thier way and some are willing to bend over backwards for you.
You are buying the vehicle and you should be able to tell them what you want on it. If they don't want to do it try a different dealership. I went to 2 dealerships when I bought our Colorado. One was a bunch of buttheads and the other treated us like kings abd gave us what we wanted.

[Carl V]

I have a 2006 Highlander. More recent models may differ, but here's how it was in my case.
My HL is an AWD V6, and in Canada all AWD V6 HL have the towing package standard from the factory (Transmission aux cooler, larger alternator, etc.) The hitch and trailer harness was not included unless purchased by the original buyer.
Mine came with a 3rd party (Reese) hitch, no harness.

My HL has a large plastic connector buried under some plastic trims at the rear left. This is where Toyota's OEM harness plugs in. It is only a 4 pin harness. Toyota doesn't install any brake controller or 12V charge line. Their harness included the converter for trailer lights, and it is a powered converter (has it's own power source and doesn't draw power from the vehicles light circuits). The wire that powers this module is powered when a fuse is inserted in the "Towing" socket in the fuse box under the hood. So all the wires required to install a trailer harness can be found in that connector (except the brake line) so no splicing at the lights wires like the old days. The thing is, Toyota's harness costs an arm and a leg, so I spliced the wires at the connector. I think you can now found these plug'n play harness kits that can be installed much more easily, no splicing.

My trailer has brakes, so I needed the 7 pin plug. I installed my own 12V charge line (AWG 8) from the HL battery to the plug (ignition switch-controlled relay), with appropriate fuses.

I installed my own 3rd party powered light converter and transferred my Tekonsha brake controller to my old minivan to my Highlander, brake line, fuse, etc. The vehicle is not pre-wired for a brake controller.
The light converter came with a 4pin plug, which I kept for my small utility trailer.

[Darral T.]

For what it's worth, my Nissan 99' PU manuals says trailer brakes are required pulling any trailer over 1000 lbs.

Run from his ADVICE! I would NOT pull that trailer without it having brakes! My truck didnt have ANY trailer wiring. I added a 4-pin first when I needed to pull a small U-Haul (I was ignorant of needing brakes then!). When I got ready to buy my Scamp, I ordered ALL the parts (from etrailer.com) and added the 7-pin from Hopkins. I bought the one where the 4-pin just plugged right into the back of it!

As someone already mentioned, you're missing the "HOT" wire to charge yer onboard battery, backup lights and MOST of all.... BRAKES!! Dont leave the dealership WITHOUT them! I would also install a "Breakaway" switch. It's cheap insurance should your trailer- for some WEIRD reason- become disconnected. Some states require them as well.

Just PLEASE get trailer brakes!

[Glenn Baglo]

My Toyota dealer brought in an after-market installer to wire the brake controller and 7-pin connection. He also installed the hitch receiver ( a class III receiver for weight distribution hitch ) and he used 10# wire that I specified.
For all that, he charged about $300 less than the Toyota class II receiver that is Toyota original equipment.
Get a quote from U-Haul or a hitch shop in your area.
You specify a brake controller and wiring for 7-pin and a class III hitch receiver for a weight distribution hitch.
The breakaway switch is installed on the trailer and isn't part of the vehicle wiring.

[steve dunham]

Some vehicle manufacturers seem to make it easy and others seem to make it difficult.
Some vehicle manufactures design their vehicles for towing others do not .
Some vehicle manufacturers make towing information and equipment required to tow , easy to access while others hide it like it’s a military secret.
When I went to buy a tow vehicle , the dealership had a whole row of tow ready vehicles.
All of them had a factory trailer hitch , 4&7 pin receptacles , transmission cooler . oil cooler,
brake controller , proper rearend ratio , towing mirrors , larger alternator etc etc.
Buying a tow vehicle should not be that difficult or require you to run to 15 different dealers or spend 2 weeks on the internet doing research
It just seems that some manufacturers want to make it so difficult to tow with their vehicles so that you give up the idea

[C&G in FL]

As Steve said, many of the vehicles which come equipped with towing packages have dual connectors so that you can plug in a 4-pin or a 7-pin connector. And as was previously stated, the small trailers for hauling lawnmowers are really the only ones now appropriate for and being supplied with 4-pin wiring.

[Captleemo]

I think you would be well advised to find a different dealer, one that will work with you and not try to BS you like your dealer seams to be doing.

[Debbie in Florida]

Wow...thanks to all of you for the great advice. I knew I came to the right place!

I want a new vehicle so I can get a factory installed tow package (I have learned that is best) and not have the hassle of adding and adapting and not being able to judge if that is done right. I was so surprised to learn that Toyota only has a 4 pin connector and am disappointed as the Highlander seemed like a fit in so many other ways.

(I am also not sure they would have provided a factory installed tow package. One of the representatives said the tow package it put in at the distribution site in Port Canaveral which made no sense to me!)

I have looked into the Ford Explorer...seems like a good tow vehicle but general SUV ratings are not up to other models. So I moved to researching the Toyota Highlander.

I will look at the Hyundai Sante Fe next (not the Sport). I test drove it and loved the ride, but have not researched it. One of you specifically mentioned the Honda, but it seemed soooo big to me. (I now drive a Subaru Cross Trek and want to keep my TV as powerful but as small as possible but still maintain the needful.) The Chevy SUV for towing also seemed like too big a vehicle for me. I drove the VW Atlas but trying to find a vehcile with a tow package anywhere in the state of Florida was an issue. And the dealership was not helpful in any way.

So, I will move on. Still welcome and recommendations you have. And thank you all again...so much. Without this help, I might be in real trouble.

[Glenn Baglo]

I would go with the Highlander with factory tow preparation package. Then I would take it to an aftermarket hitch installer to wire the brake controller and 7 pin and install a Class III hitch receiver for weight distribution hitch.

[Jon in AZ]

Agree with Glenn. If you like the Highlander AND you can find one with the factory tow package, buy it. The small extra trouble finding an installer for the hitch and wiring will be soon forgotten.

[Steve Carlson]

I wouldn't hesitate to take a Highlander with factory tow package and have an RV shop install a 7-pin harness, and brake controller if needed.

[edit] Oops, you guys got there first.

[CarlD]

I agree with Jon and Glenn. Toyotas have a very good repair record. We have owned many of them and never had a major problem, other than rusting to pieces in upstate New York like every other vehicle!

[Glenn Baglo]

Originally Posted by Jon in AZ

The small extra trouble finding an installer for the hitch and wiring will be soon forgotten.

No trouble, and cheaper by several hundred dollars in my experience. Toyota wanted $950 for their Class II hitch receiver ( which wasn't beefy enough for WDH ). Brake controller and 7-pin wiring was extra.
The installer that the dealer used charged me $650 for a superior hitch receiver and all the wiring.

[Jon in AZ]

OTOH, since you mentioned size, you might want to visit a Kia dealer and take a look at the Sorento. It is a corporate sibling of Hyundai and uses the same powertrains as the Santa Fe and Santa Fe Sport. It appears to be a little more compact than some of the others.

Jeep Grand Cherokee is also a more compact vehicle with a similar row rating.

[Huck]

I went to etrailer and entered 2018 Toyota Highlander and it doesn't show any 7 pin wiring harnesses available, only 4 pin.

[Debbie in Florida]

Thanks for doing that Huck.

I will check with a local RV shop and see what they think they can do with a new Highlander, or may even look at a used one and save some money being that I will doing adaptations.

Jon, I will check out both vehicles you mentioned. I was going to just stick with the Hyundai since I knew the Kia Sorento was similar. It gets overwhelming to keep looking, at least for someone like me who does not find this fun. Just want the right vehicle for my needs so I can have fun.

I did read that the Jeep was not the best for towing in spite of its outdoorsy reputation.

I will keep writing and asking questions as I continue to research, test drive and feel confused. Keep any ideas and opinions coming. It really helps novices like me but, I am starting to know more than the dealers thanks to what I am learning from reading and learning on this site from all of you.