How to connect a trailer brake controller to a (late?) 100 series TLC

[e9999]

Here is a brief rundown on how to find and use the connector for a trailer brake controller on the 100 with tow package.


(The following is for an '03, but likely to be the same or similar for later years. It is
likely that the connector may not yet have been put in on earlier years. Check your EWD. My guess is that the connector is present when the tow package includes a 7 pin trailer socket in the back, and probably not when the tow package includes only the 4 pin socket. Having seen what a believed to be an 02 EWD that did not show the brake controller connector, I believe the connector may have been introduced in 03.)

This connector is well hidden under the dash and not readily visible. It is not obvious at
all how to get to it. So thanks to Dickballard who posted some instructions on Edmunds.com that proved most helpful.

The connector is intended to provide you with all the wiring needed for a brake controller. If you use it, there is no need for any splicing, wire cutting and wire laying. It's great!


There are 2 possible ways to get to it. A sure thing but longer, and a possible quick fix that may or may not work for you.

Location: The connector is located on a harness right behind the metal knee brace under the lower plastic panel, about a foot above the accelerator pedal towards the driver. This
white connector (5 wires) is branching off a harness and located between the lower transverse plastic vent conduit and the metal knee brace, or perhaps above the conduit. I
don't believe it is visible from under the dash without removal of parts.


Quick method (without removing the lower plastic panel at the bottom of the dash) [Note I have not actually tried this so I'm guessing here based on what I saw when I took the whole thing apart]: if you go on your back and look up under the dash, you will see a long (about 1 ft) wide (2 - 3") black plastic conduit for air ventilation that connect from the center radio "tower" to the area near the mirror controls. This is close to the bottom of the dash assembly. It is a vent carrying air. This conduit is held by a single golden screw on the bottom left side. This screw is not reachable by a screwdriver unless you remove the lower plastic panel, but can likely be unscrewed with pliers from the side otherwise. After you remove this screw, the entire conduit can be removed by gently twisting and turning it. It is held by the 2 ends simply by being inserted in similar fixed tubes. You may need to twist, bend, pull, and push. Be careful. There is a lot of stuff down there. If you are successful, and remove it this way, look right behind the metal knee brace, in line with the accelerator or so, and you may see a single white squarish connector, empty with about 1" or wiring out of a big black harness. That's it. (It's not the white connector located way up close to the top with a single black wire into it.) The wires going into the correct connector are White, Green, White/black, Green/white, and White/blue. Plug your pigtail connector (see below) in that one, let the wires hang, and put everything back together after checking for voltage etc. If this worked, you are lucky.


What I did instead is take all the panels off. Start by removing the horizontal plastic
bezel above the steering wheel, the one that has the light dimmer in. It comes right out by pulling on it. Then (or first, I forgot, check), remove the circular trim around the
ignition key slot (careful, you must turn it and pull to remove it, there are tabs that have
to be aligned with slots). It should then be possible to remove the entire lower plastic panel (in front of the driver shins and knees). To do this, remove the single black screw
on the very left edge, close to the door. Then remove the 4 screws holding the 2 handles
for the hood and gas door. The lower plastic panel can then be removed by pulling gently,
there are 4 or 5 clips holding it, all around. There will be several switches and harnesses
into it. Watch out for the skinny one on the right, those wires are small. You can disconnect all the harnesses and remove the panel. Next comes the metal knee brace. It's
held by 4 or 5 bolts and comes right off. After that you will clearly see the black plastic
vent I mentioned earlier and maybe even the connector, in front or above it. If you don't
see the connector, remove the vent conduit as described above and the connector should be visible. Again, connect your pigtail (see below) and put it all back together after checking for voltage.

Now, to take advantage of this connector you'd want to plug something in. To my surprise
there is no corresponding male connector sold by Toyota for the Landcruiser. Fortunately,
it appears that the Tundra/Sequoia connector fits just fine. I bought the one p/n
82132-0C010 from Toyota. (I have seen less expensive pigtails for Toyotas available from aftermarket trailer places but don't know if they will work or not.)

This male connector fits in the female one under the dash and has about a foot of loose
wiring dangling from it. Connect this pigtail to the connector under the dash. Before you
put all the dash back together, btw, you may want to check for voltage on the various
terminals of the connector based on the EWD. Test for voltage supply, ground, and a signal from the brake pedal. There is one wire (for tail lights?) that is not used for the brake controller.

So now your dash is back together and you have 5 wires dangling from underneath above the accelerator (note that the colors on the pigtail are NOT the same as the wiring to the dash connector). Buy a good brake controller (I got the Tekonsha Prodigy, a late generation solid state gizmo that is supposed to be top of their line and perhaps the best out there). The prodigy came with a harness, and instructions on how to connect to the Toyota pigtail by colors. I checked with the EWD and the instructions were correct. Note the controller only uses 4 wires. I connected the wires with quick-disconnect spades crimp-ons. I used 2 different sizes and alternated male and female so there can not be any mistakes when connecting it (I am using this controller in 2 trucks and move it around.) Pay attention to the minimum gauge requirements and be sure there is an appropriate fuse in the circuits (there is one already on the 03 wiring system apparently). I mounted the controller on the lower edge of the lower plastic panel, about even with the accelerator (I checked the inclination and orientation of the controller mount and it was within specs).

Check to make sure all the voltages are as should be, both at the controller and trailer socket in the back.

Go get yourself a treat. You're done!

HTH

Eric

[spressomon]

Eric,
I need to add a 7-pin trailer wiring connector along with a e-brake controller to my '99. Have you been satisfied with your set-up you posted sometime ago (above)?

Thanks,
Dan

[wngrog]

Quickest method was to take it to the local RV place. They charged me $50 for the install.

I would rather pay that than read all of that

[e9999]

well, as discussed elsewhere, I discovered a design flaw in the OEM tow circuitry that allows trailer battery feedback into the instrument cluster... Idiots! and not willing to fix it either...! had to rig something up the day before going on a 2 weeks long trip...

[EdsCruisin]

My '00 LC must not have the tow package. I did not know about the under dash connector, but I found the connector near the rear muffler. It is a 4 pin female for lights only. I went to the dealer for the other end too, and they don't make that one either! The Tundra version is different too.

That was OK because I prefer to use an isolated circuit for my trailer electrics. I had a short once that locked up a van dashboard, right as I was about to pull out of my driveway. I strongly recommend hardwiring a mini fuse box to the battery and running independent circuits for the lights, brakes and 12V outlets. A heavy duty trailer wiring relay from e-trailer.com is the best way to preserve your electronics. It all fit in the left rear pillar.

[Living in the Past]

Originally Posted by EdsCruisin

My '00 LC must not have the tow package. I did not know about the under dash connector, but I found the connector near the rear muffler. It is a 4 pin female for lights only. I went to the dealer for the other end too, and they don't make that one either! The Tundra version is different too.

That was OK because I prefer to use an isolated circuit for my trailer electrics. I had a short once that locked up a van dashboard, right as I was about to pull out of my driveway. I strongly recommend hardwiring a mini fuse box to the battery and running independent circuits for the lights, brakes and 12V outlets. A heavy duty trailer wiring relay from e-trailer.com is the best way to preserve your electronics. It all fit in the left rear pillar.

I not sure about the land cruiser but when I wired up the trailer lights in an 01 Tundra there was a 30 amp fuse holder that bolted to the positive terminal of the battery then pluged into the factory wiring harness. Then I had to add the relay box in the back. This was all toyota wiring I got from a dealer, so on the Tundra at least the trailer wiring is isolated from the rest. It took me four dealers before one who find the part numbers, the other dealers told me it was unavailable. This was in 04 on an 01. My 2000 LC has the factory hitch and trailer wiring but I don't have the FSM for the wiring yet so I don't know if the LC trailer wiring is isolated like the Tundra. Has anybody checked this out? I hate to think the wiring in the Tundra was better engineered than the Land Cruiser.

On the 04 4Runner we have the male plug for the brake controller came with the vehilce along with the head unit and pin for the reciever hitch. Maybe the 4runners got this since the reciever hitch was standard on all 4Runners.


John

[ECruiser]

This thread saved me a ton of time. I used the "quick method" to access the connector for my '06 100 and it worked great. The gold screws holding in the vent tube actually had hex heads making it even easier. Don't get me wrong, it still was a pain in the a$$ getting that vent tube in and out but much better than pulling the lower dash.

Also note. the Techonsha Prodigy fits nocely in the ashtray slot of my 100.

Thanks

[boze_man]

Originally Posted by e9999

well, as discussed elsewhere, I discovered a design flaw in the OEM tow circuitry that allows trailer battery feedback into the instrument cluster... Idiots! and not willing to fix it either...! had to rig something up the day before going on a 2 weeks long trip...

hey all...i have an 03...

was looking at this great write up but now not sure what needs to be done...is there a flaw to the OEM system? should i just goto a rv place and have them do an install?

thanks
the dude

[e9999]

the flaw is that the battery in the trailer will power some stuff in the instrument cluster (and maybe lights) when the key is partially on. So I put it in a relay to stop that.
There is a TSB on something related.

[100 TD]

Originally Posted by boze_man

hey all...i have an 03...

................... should i just goto a rv place and have them do an install?

ONLY if you know for a fact they solder connections and don't use scotch loks etc. and are auto electricians. On the other hand, just because someone charges the earth doesn't mean they know what they are doing, and will do it correctly. Maybe someone on MUD is an auto electrician in your area and can personally do a proper job. A modification to the Toyota system that is flawed, may also be an option, as posted above. Good Luck!

[boze_man]

thanks for the feedback guys...i am gonna go the OEM route with some sorta fix...i called my wrench at the dealer (good guy) and he is looking into a possible TSB etc ...so if i learn anything will post here

[CrusrDug]

Definitely report back. I was considering the same thing because I have surge brakes now and HATE THEM. They heat up way to fast on descents and my bearing buddies get so hot they really pop out.

[rwheelz]

Note to all: after reading the above description, I was able to plug in my prodigy controller using the Tundra harness without removing anything at all. Lay on your back looking up under the dash, squeeze the plastic air vent conduit and it compresses easily- you can see the white connector without even removing it, and I plugged it right in. It literally took me minutes, and with the tundra harness it is literally plug and play at both ends (you do have to ground one wire).

[TXLX470]

Which year is your LC??

[e9999]

Originally Posted by rwheelz

Note to all: after reading the above description, I was able to plug in my prodigy controller using the Tundra harness without removing anything at all. Lay on your back looking up under the dash, squeeze the plastic air vent conduit and it compresses easily- you can see the white connector without even removing it, and I plugged it right in. It literally took me minutes, and with the tundra harness it is literally plug and play at both ends (you do have to ground one wire).

good to know, but I'd be really carefully about squishing anything under there, you don't want an air duct to split...


(oh, and still very happy with my Prodigy...)

[rwheelz]

Yeah that air tube is really made from a pretty soft plastic... give 'er a squeeze and you will see what I mean. You don't need to compress it much at all to see that clip- I did use a mirror when I was first looking for it but sticking your fingers up there in the exact spot described above is enough to find the connector.

Did you mount your prodigy in the ashtray? I can't seem to get the black plastic ashtray surround out so I can drill the back to run the prodigy wiring through. I didn't want to drill blind for fear of hitting something important behind it.