Installing brake controller

DABWCA

For newbies without a tow vehicle already wired to plug and play a brake controller, getting ready to tow a T@B isn't always straight forward. Even if you have a hitch and a 4-pin connector, you still need to patch in a 4-way to 7-way adapter and run a fused charge line to your tow vehicle battery. With a hard wired controller, it also means running additional wiring from the brake line to the controller.

I recently bought a 2015 KIA Sorento that's equipped with a hitch and 4-pin connector. And my long awaited special order T@B-L is now at my dealer. So I now need to get my tow vehicle ready to tow. That means getting wired for a 7-pin and buying and installing a controller. I will be buying either a Tekonsha P3 that would be mounted under my dash or a Tekonsha RF that would bolt to the T@B tongue. 

Most places, including ETrailer.com, seem to run the charge and controller wires under the vehicle, weaving them around the various components down there but staying completely outside of the vehicle. The wires are generally tied or fastened to hold them in place but not protected in any other way. My Minnesota T@B dealer advises not to run the wires that way but rather to run them inside the vehicle for better protection. Because the KIA isn't a truck, where wires can be run through the frame, that means routing through the rear wheel well and underneath the door sills or carpet and probably a bit of disassembly/reassembly.

So now I can use some advice about the best way to get wired to enjoy my T@B, which will live outside in Minnesota. Here's what would be really useful to know:

1. What's your tow vehicle?

2. What brake controller are you using?  Where is it mounted? Does this setup work well for you?

3. Was your tow already equipped with a 7-pin connector so that you could simply mount and plug in a brake controller?

4. If your tow vehicle wasn't already equipped for a controller and needed wires run from back to front, what was the wiring route? Completely outside and under the vehicle, underneath the vehicle but mostly through its frame, or completely inside the vehicle?

5. Do you feel that your wiring is adequately protected from the elements, especially if your T@B is stored outside in a harsh climate?

I apologize in advance to all of you good people if I'm showing too much newbie anxiety, but I'm thinking that at least a few other newbies would be interested in learning from your experiences. There are no right our wrong answers, just helpful insights!

Nomad

My MN dealer recommended having U-Haul install it and I have no idea what they did in and under my Jeep. I went the cheap controller route and have never been able to adjust it to my satisfaction so 90% of the time I have it shut off. I have a stick so I just downshift on those 6% grades. The only time I felt I needed it was going down a very long 9% grade out of Death Valley where I turned it on. Every vehicle is different but the weight of my Jeep seems to do just fine but At some point I plan on replacing the controller.

JandJ92010

We tow our T@B with a Ram C/V van, the dealer installed the "Tow Package" which is the hitch and light wires. I had to install the brake controller myself. I already had a controller, it's a timer based style (cheaper) and instead of trying to wire it to the brake light switch (6 wires?) I bought a foot switch from Grainger and wired the brakes through that. Works great, if I need brakes, push the foot pedal, if not don't. I mounted the foot pedal on the left foot footrest. I mounted the controller on a sheet metal bracket and Velcroed that to the top of the dash next to the "A" pillar. Didn't have to drill any holes and if I need to work on it I just pull it off the Velcro, ran the wires down between the dash and the door, so I have some slack there too. I ran the wires under rather than through the van, covered them with wire shield and zip-tided that to brake lines, frame, anywhere it will be out of the way. Should hold up.    Have fun!

Verna

I plan to install the Tekonsha RF.  To me, it's simpler, though more expensive. I do not have it yet, so I am relying on the expert advice from a very experienced owner.  I expect to install it myself on my 2015 Toyota Tacoma V6 4x4 TRD Off Road and on the tongue. All other wiring is already in place from the factory on the Tacoma, and I understand I just have to drill two holes in the tongue, mount the controller level, and plug the 7 pin plug into the controller, while using the other end of the controller's wiring will then plug into my Tacoma.  

DurangoTaB

2012 Tacoma TRD (with tow pkg), Tekonsha P3, mounted above my left knee...works great...esp going down our steep Colorado passes. 

Nomad

DurangoTaB - How steep? Seems the standard steep grade is 6%. Have only hit two that were steeper. 9% feels like your on the big downslope of a roller coaster.

Verna

DurangoT@B, mine has the factory tow package with the transmission and oil cooler.  One of the big deciding factors to buying it.  I don't live life on the edge, and I don't want to go over an edge as I head downhill !

Normfun

Verna if you have the tow package the wired controllers are plug and play. Mine took reading the manual twice then 5 minutes to install. I did the install at a campground. Very easy. Hey have you found one yet?  White and red. Right? 

Michigan_Mike

One of the longest grades I traveled (don't know the % of the slope) was coming out of the Bitter root Mountains headed for McCall, Idaho.  I was praying on the way down and hoping that my brakes wouldn't fade as it seemed like it would never end....  Yes, I was sweating bullets!   

Nomad

Know the sweating bullets feeling - I'll never take the west exit out of Death Valley ever again - long, winding 9% grade - 7,000 ft down to 3,500 (as I recall). Felt like you were in free fall.

mawebb

I have a Honda Pilot Touring which was pre-wired with a 7 pin connector. I installed the Tekonsha P3, which I mounted to the dash then simply plugged into the existing harness. 

Note that proportional controllers must be mounted appropriated to allow the deceleration sensor to measured the braking force. Time based controllers can be mounted in any position. 

In terms of protecting wiring external to to vehicle it can be protected by using wire loom. 

Dont forget to either add a relay on the charge circuit or a battery isolator to prevent the T@B from draining the TV battery when still connected but not driving. 

DurangoTaB

Red Mountain Pass, on a good day, is like a roller coaster!
https://www.codot.gov/travel/maximum-grades-on-colorado-mountain-passes.html

Nomad

Red Mountain's a wimpy 7% :-)

Michigan_Mike

I've been over Red Mountain pass many times and love the area and it's never been an issue.  I'm like most folks and courteously pull over to the side of the road in a pull-off area when traffic starts to build behind me on any mountain grades.  I've chuckled a few times too along the trail as I've seen some large trailers with indentations and scrape marks from rock outcroppings via the Rocky Mountains.  

Nomad

Steep...The standard steep grade seems to be 6% - What amazes me is how much steepness each additional 1% adds.
Scrapes...The coast highway isn't a good road for longish rigs either. No way they can make it around those curves without scraping up the whole side.

Michigan_Mike

When I do get a T@B I will have a good brake controller and good pads on the vehicle.  People often wonder why they won't let them take trailers like the Little Guys, etc, up and over "Going to the Sun" road up in Glacier, but once you drive up and over Logan Pass it hits home pretty good.  The narrow passages would no doubt result in quite a few crumpled heaps of aluminum hulks and skeletons sitting on the canyon floor below, as you often see in Colorado.  Scary areas for sure and white knuckle city too!  

Lisa33

Bah...Red Mountain and Death Valley are cake.  Mt. Washington in NH averages 12%.  . http://mtwashingtonautoroad.com/drive-yourself/

Nomad

12% - What do you do, rent a mountain goat and hook it up to your TV?

DABWCA

Those of you with the luxury of factory wiring for 7-pin connectors are in great shape with plug and go brake controller setups. Sadly, even factory "tow-ready" offerings for many vehicles are only wired for 4-pin connectors.This includes with Subarus, Ford Escapes, Kias, Hyundai's, Highlanders, VWs and some other vehicles that are rated for up to 3,500 pounds. Many of us are left with some additional wiring for a controller. 

I'd love to learn what T@Bbers did who were not already set up with 7-pin wiring. 

1. What's your tow vehicle? 

2. What brake controller are you using?  Where is it mounted? Does this setup work well for you?

3  If your tow vehicle wasn't already equipped for a controller and needed wires run from back to front, what was the wiring route? Completely outside and under the vehicle, underneath the vehicle but mostly through its frame, or completely inside the vehicle?

4. Do you feel that your wiring is adequately protected from the elements, especially if your T@B is stored outside in a harsh climate?

Thanks to all of you who have responded thus far. They include some interesting cautionary tales about crazy step grades to watch out for.

Nomad

My Jeep Wrangler with factory tow package came with the four pin - Took the T@B dealers advice and had the uHaul dealer install the seven. I just got the cheap controller and I have no idea where they strung the wiring. The controller's mounted in front of mt right knee - Took them an hour or so.

remphoto

Just had controller installed on new 2015 Pilot EXL. All Pilots now come with factory tow packages prewired for controller and 7 pin plug. The top of line Touring model has plug preinstalled at factory.   It cost me about 400 for the controller and plug and installation.  Could have done controller myself as it is plug and play but the 7 pin plug requires disassembling part of the cargo compartment so left that to dealer.  Surprisingly, the hitch took a 6" drop to get to 16" to top of ball.  Hoping to see our new Sofitel S built at factory next Monday and  pick it up at Dealer later on week week (we fortunately live in Ohio). 

wizard1880

TV is a 2004 Jetta TDI, Tekonsha P3 mounted above the right knee. The way I have it set up it almost feels like the trailer could do the braking for the entire car if I crank it high enough.

Things that I find that really make a difference are, we had an 8 gauge wire routed directly from the battery (+ and -) to the trunk area where the 7 pin receiver is kept. I also ran a 10 gauge wire from the brake controller so plenty of amps get to the brakes. We had a car stereo shop do the wiring so it is all kept inside the car, hidden behind panels and thru existing wire conduits.

We have a battery monitor installed in the camper so we can watch how much juice makes it back there. With the heavy gauge wiring we see 14.3v in the camper when the car is running, and the battery almost full when we get home.

DABWCA

Wizard, Thanks! That's a really helpful description of your setup. Keep up the T@@bulous fun.

ChanW

The 8ga wire is smart, I think. I used the kit that eTrailer sells, and the heavy wire going back to the 7pin connector is only 10ga.

The voltage drop would depend on how much current is on the wire at that moment, wouldn't it?

I'll have to check the voltage drop back there, at various states of charge, and varying current demands.

DABWCA

Chan - Did you route your wires underneath your chassis as most of the etrailer videos show or did you follow an internal route? Do you think it matters? What kind of vehicle do you drive? What controller are you using? 

mawebb

Voltage drop is a factor is resistance. Copper wire resistance is affected by length and gauge. The shorter and larger, the less resistance therefore bigger and or shorter is better. There is a limit to the guage as the 7 pin connector is limited to a maximum wire guage based on its physical characteristics. 

moniraq

I just posted a question regarding the Tekonsha Prodigy RF EBC. I have a brake controller already but I'm thinking about replacing it with the wireless one.

DABWCA

I've been thinking about this for some time and have received some helpful advice about the RF.  The discussion is active and recent. It should be easy to find.

moniraq

Found it. I did a search for "brake controller" before posting and nothing relevant came back. I should have searched for the name of the controller. Thanks for the heads up.

ChanW

David, I installed the eTrailer kit under the chassis - not much choice, it's a Tacoma pickup. I laid the wires in the same place the existing wires went.

I feel fine about it. It's all tightly hung with zip ties. Any connections that are potentially exposed to puddle splashes, I covered thoroughly (I might have gooped them, I don't recall now). I also wrapped them with the corrugated plastic wire-covering that car manufacturers use.

I'd installed the nice Tekonsha controller and it was all ready to go. We arrived at the dealer and the brake actuator turned out to be hydraulic surge! Oh well. The hydraulic works fine, and is less complicated.

wizard1880

ChanW said:

The 8ga wire is smart, I think. I used the kit that eTrailer sells, and the heavy wire going back to the 7pin connector is only 10ga.

The voltage drop would depend on how much current is on the wire at that moment, wouldn't it?

I'll have to check the voltage drop back there, at various states of charge, and varying current demands.

Yep, that's what I notice. When we plug in to leave, I've seen the current rushing to the battery between 15 and 25 amps, and dropping to 5 or so after a few minutes. At that time the voltage is in the 13v range, and makes its way to 14+ as the battery tops up charge.

I believe the 7 pin connector is only 10 gauge itself, but I wanted as much current as possible available back there for charging the battery and running the camper's taillights nice and bright (via the powered taillight converter).

I realize that most folks tow with vehicles that are prewired with factory kits, and you're pretty much stuck with it unless you want to customize it or bulk up the wiring yourself. Since I'm a bit of a nerd with electrical engineering I went a little nuts with my custom setup.