12 Volt Source for Toyota Highlander?

JeffGeb

We are new T@B owners and have just purchased a 2018 Toyota Highlander to pull it. The T@B has a 7 Pin Electrical Connection, but unfortunately, the Highlander has (only) a 4 Pin Connector. I have installed a 4/7 Pin Adapter to the Highlander and the lights, blinkers, and brake lights work fine. I am now only in need for a 12 Volt source to hook up the (black) lead to the 7 Pin Adapter to provide for the continuous power from the Highlander to the T@B. This will provide for battery charging in the T@B while traveling and a backup battery source while in camp. Has anyone had this connection made in a Highlander? Ideally, I'm looking for a continuous 12 volt source in the back of the vehicle so I don't have go through the fire wall for a direct line from the battery and tear apart the interior to run such. I can, of course, take it to my T@B dealer to have it done, but if there is an easy source in the back, I'd rather do it myself. Anyone?  

xbooooo

What about the T@B's electric brakes?

JeffGeb

Ours is a 2016 320 CS-S. Didn't think it had electric brakes. Am I wrong? It has a surge brake cable so I'm assuming that that is all it has. 

ScottG

I'm not sure what you are calling a "surge brake cable" but your 2016 most certainly has electric brakes.

While the T@B isn't a huge trailer, it's heavy enough that you want those brakes operational. It may even be a legal requirement in some places. To use the brakes you will need a brake controller and have the tow wiring upgraded in your Highlander.

You might be able to "cheat" by using a wireless brake controller. However, I don't have any firsthand experience with these--hopefully someone else will chime in with some advice if that is a possibility for you.

xbooooo

Maybe your "surge cable" is the emergency brake actuator if the T@B breaks away from the tow vehicle. 

JeffGeb

Thanks,all! We bought our T@B privately so haven't had any dealer support. I guess I will make a trip to the dealer on Monday.

MuttonChops

@JeffGeb
Suggest you visit your Toyota Service Department not your T@B Dealer for help or installation for the 7-pin wiring.  Toyota will know your vehicle wiring.

I've not been able to locate any Highlander Wiring Diagrams on 'the web" and you would be working blind without that type of reference material.

Your Highlander Owners manual does have two interesting notes:
a)  For trailers over 1,000 pounds trailer brakes are required.  You do need to add a electric brake controller to your set-up.
b)  For trailers at/over 2,000 pounds a sway bar is required.  Now user experience (Highlander owners on this forum) might say that is not needed but Toyota believes it is.

jason330i

Hello, instead of running the 12v wire through the cabin, you should run it under the vehicle on the drivers side. Have the wire come up through the engine bay and connect to your vehicles battery through a fuse or breaker. Also look into a wireless brake controller so you don’t have to run additional wires into your cabin.
The website etrailer.com has lots of good info.

Marceline

ScottG said:

I'm not sure what you are calling a "surge brake cable" but your 2016 most certainly has electric brakes.

While the T@B isn't a huge trailer, it's heavy enough that you want those brakes operational. It may even be a legal requirement in some places. To use the brakes you will need a brake controller and have the tow wiring upgraded in your Highlander.

You might be able to "cheat" by using a wireless brake controller. However, I don't have any firsthand experience with these--hopefully someone else will chime in with some advice if that is a possibility for you.

I don't think that it's fair to suggest that a wireless controller is a "cheat." I have surge brakes so this isn't an issue for me, but many people seem very happy with the wireless controller.  I had a long discussion with the owner of the shop that installed my 7-pin connector and he said that he recommends them to just about all of their customers. The upfront cost is higher but there is no installation cost and he also said that it is virtually impossible to wire an aftermarket controller in some high end European cars. Also, the wireless controller can be moved from one tow vehicle to another. 

From etrailer, here's some info on trailer wiring for a 2017 Highlander, which I assume would be similar to the 2018.
https://www.etrailer.com/question-200706.html

ScottG

Marceline said:

ScottG said:

...
You might be able to "cheat" by using a wireless brake controller.
...

I don't think that it's fair to suggest that a wireless controller is a "cheat."
...

Unchallenged. That was said tongue-in-cheek, hence the quotes. I did not intend to imply that a wireless controller was an inferior solution, only that it may allow the user to get around the problem of not having a hard wired trailer brake circuit.

Sharon_is_SAM

JeffGeb, I believe you need to have the charge line come off directly from the battery.  A good utility trailer shop can install your charge line.  I highly recommend having them use a minimum of 10 gauge for both the charge line and the ground for the TV 7-pin.  This will limit voltage drop and improve your charging ability.  If you read enough on the forum, you will find many folks have problems keeping the 3 way frig going on DC without depleting the TaB battery.  I know your 2 way frig is much more efficient, but it is best to optimize your charging ability from the onset.  

I am not sure what you mean by a backup battery source.  If your Tab battery is significantly depleted you would need to run the TV quite a while to recharge your TaB battery.  Also, keep in mind, the after market charge lines that are installed without an isolation relay are always hot.  So, if you stop for sight seeing for an extended time, you can potentially draw down your TV battery.  If you have your charge wire done in an auto shop, they can install an isolation relay that cuts power when the ignition is off.

Regarding the brake controller:  I agree with Jason.  We have the Prodigy RF Brake controller.  No further wiring needed.  Pretty much plug and play.  

Photomom

We had a good trailer shop set up our 2013 Highlander when we going our 2016 T@B. For whatever reason, our Toyota dealer would not do it. And I didn’t trust our T@B dealer to do the work. 

They installed a 7 way connector beside the hitch and installed a Tekonsha P3 brake controller. You have electric brakes in your 2016 and need some sort of brake controller. They also ran a fused heavy gauge 12v line from the battery back to the appropriate pin on the 7 way. 

JeffGeb

Thanks, everyone. I have ordered the Tekonsha Wireless Brake Controller and have an appointment to have the battery wire done this week. We'll be ready!! Looking forward to getting on the road.

dragonsdofly

@JeffGeb, great choice. We have the tekonsha wireless brake controller set-up and it's easy, efficient and convienient. We have over 18,000 miles on the trailer through deserts, mountains and even in the atlantic ocean for a bit, and the system has operated flawlessly. Another trouble free incident occurred when our tow vehicle was totaled only 3 weeks before departure on a once in a lifetime vacation. We took the controller out of the smashed vehicle and plugged it into the replacement vehicle and ta-da! We were immediately ready to tow. One less headache in a mess of paperwork and technicalities! The vacation was delayed by only a few days, and our boys had a never to be repeated adventure! 

Rolltide82

I now have a Tundra with tow package ... I wonder if I need to run a larger wire from my 7 pin.  My tokensha was just plug and play... 

Sharon_is_SAM

What is your alternator output?  Do you have the 3 way frig?  See if it maintains the frig temp first.  Can’t beat the wireless brake controllers!

Rolltide82

I have the 3 way....however I rarely use the fridge..  I have 2 yeti coolers and honestly camp 2 days at the time mostly due to work....and I only drive one hour from my house to the main grounds we camp at

Sharon_is_SAM

Sounds like no current need to upgrade any wiring

drazilgod

We have a 2013 Highlander, the RV place installed a 7 pin. For what its worth, we run our brake controller to zero all the time. I tow a lot of heavy equipment and two trailer places told me that if a trailer is under 3000 pounds and if the trailer is less than 40% of the tow vehicle's GVW, trailer brakes were not required in Maryland or anywhere they knew of. They thought the brakes would be of no help at all. That said, if @MuttonChops says the Toyota manual recommends brakes, then that's probably a good idea. Sorry for the back and forth.
However, you originally asked about charging and a 4 pin. I ordered a 7 to 4 pin adapter and added a 2 wire piece of cord which alligator clamps directly to the battery terminal. I can send a link and pics if you are interested. I use it when my buddy with a 4 pin tows my T@B with his pickup. It does seem to charge the T@B battery. No brake control with this setup, though.