1. Welcome to Tacoma World!

    You are currently viewing as a guest! To get full-access, you need to register for a FREE account.

    As a registered member, you’ll be able to:
    • Participate in all Tacoma discussion topics
    • Communicate privately with other Tacoma owners from around the world
    • Post your own photos in our Members Gallery
    • Access all special features of the site

T7 Towing Brake T harness info

Discussion in '3rd Gen. Tacomas (2016+)' started by caribe makaira, Oct 1, 2019.

  1. Oct 1, 2019 at 3:35 PM
    #1
    caribe makaira

    caribe makaira [OP] Well-Known Member

    Joined:
    Feb 13, 2011
    Member:
    #51121
    Messages:
    6,239
    Gender:
    Male
    Caribbean, Puerto Rico
    Vehicle:
    05 PreRunner TRD Offroad AutoTrans
    Hood Struts, My version Fogs always ON, Map & Overhead Light Mod,
    upload_2019-10-1_18-30-40.jpg

    upload_2019-11-27_19-9-51.jpg

    For those who don't tow as much and for those who do. Tap for a "hot" 40A fuse (add a fuse holder for your toys:bananadead:), acc illumination and a ground.

    Didya @tonered ?
     
    Last edited: Nov 27, 2019
    shakerhood likes this.
  2. Oct 1, 2019 at 4:04 PM
    #2
    tonered

    tonered tacorider

    Joined:
    Sep 25, 2017
    Member:
    #231055
    Messages:
    24,580
    Gender:
    Male
    First Name:
    tony
    Lynnwood, WA
    That looks like it. Good power.
     
  3. Aug 27, 2020 at 9:42 AM
    #3
    daveeasa

    daveeasa Slowest crimp in the West

    Joined:
    May 14, 2020
    Member:
    #328079
    Messages:
    2,667
    Gender:
    Male
    First Name:
    David
    San Diego
    Vehicle:
    2016 OR 4x4 DCSB MGM 6MT
  4. Aug 27, 2020 at 9:56 AM
    #4
    daveeasa

    daveeasa Slowest crimp in the West

    Joined:
    May 14, 2020
    Member:
    #328079
    Messages:
    2,667
    Gender:
    Male
    First Name:
    David
    San Diego
    Vehicle:
    2016 OR 4x4 DCSB MGM 6MT
    Oh and it looks like most of these aren't fully pinned? I thought I read somewhere that this plug also has dash illumination? Would be sweet to get one harness which can light switches _and_ tap aux power. Still hunting for something like that but not totally sure the factory connector supplies all of the pins?
     
  5. Aug 27, 2020 at 9:58 AM
    #5
    tonered

    tonered tacorider

    Joined:
    Sep 25, 2017
    Member:
    #231055
    Messages:
    24,580
    Gender:
    Male
    First Name:
    tony
    Lynnwood, WA
    daveeasa likes this.
  6. Aug 27, 2020 at 10:02 AM
    #6
    daveeasa

    daveeasa Slowest crimp in the West

    Joined:
    May 14, 2020
    Member:
    #328079
    Messages:
    2,667
    Gender:
    Male
    First Name:
    David
    San Diego
    Vehicle:
    2016 OR 4x4 DCSB MGM 6MT
    Oh, a DIY harness with spades jammed in, I could do that, sounds like a good option if it doesn't fall out...
     
    tonered likes this.
  7. Aug 27, 2020 at 10:05 AM
    #7
    tonered

    tonered tacorider

    Joined:
    Sep 25, 2017
    Member:
    #231055
    Messages:
    24,580
    Gender:
    Male
    First Name:
    tony
    Lynnwood, WA
    It has been great for a long time. With it behind the kick panel, no unintentional problems.
     
  8. Aug 27, 2020 at 2:17 PM
    #8
    caribe makaira

    caribe makaira [OP] Well-Known Member

    Joined:
    Feb 13, 2011
    Member:
    #51121
    Messages:
    6,239
    Gender:
    Male
    Caribbean, Puerto Rico
    Vehicle:
    05 PreRunner TRD Offroad AutoTrans
    Hood Struts, My version Fogs always ON, Map & Overhead Light Mod,
    Most Electronic Brake Modules don't use the Illumination Circuit, but the vehicle side has it. It uses a 090/2.3II terminal. Look at first post.
    upload_2020-8-27_17-22-7.jpg
    Vehicle Side...
     
    Last edited: Aug 27, 2020
  9. Aug 27, 2020 at 2:42 PM
    #9
    daveeasa

    daveeasa Slowest crimp in the West

    Joined:
    May 14, 2020
    Member:
    #328079
    Messages:
    2,667
    Gender:
    Male
    First Name:
    David
    San Diego
    Vehicle:
    2016 OR 4x4 DCSB MGM 6MT
    Yeah, I'm hunting for something I can buy which would be pinned there b/c I am trying (and it seems like I'm losing) to avoid buying a crimper and proper terminals...

    So Power, Ground, Brake, Tail, Stop, one of those is illumination? The green one marked tail? I assumed it was for taillights, brake for brake lights, but then I wasn't sure what's different between brake and stop unless stop is for controlling the force to apply to the trailer brake?
     
    tonered likes this.
  10. Aug 27, 2020 at 2:46 PM
    #10
    tonered

    tonered tacorider

    Joined:
    Sep 25, 2017
    Member:
    #231055
    Messages:
    24,580
    Gender:
    Male
    First Name:
    tony
    Lynnwood, WA
    Oh man. I just did that for my Viair project. Freaking satisfying to have the proper tools. Just get 'em!

    https://www.tacomaworld.com/threads/viair-automatic-mod-vam.680478/

    Honestly, they have me thinking about re-crimping this power tap just for the fun it. :D
     
    daveeasa likes this.
  11. Aug 27, 2020 at 2:47 PM
    #11
    caribe makaira

    caribe makaira [OP] Well-Known Member

    Joined:
    Feb 13, 2011
    Member:
    #51121
    Messages:
    6,239
    Gender:
    Male
    Caribbean, Puerto Rico
    Vehicle:
    05 PreRunner TRD Offroad AutoTrans
    Hood Struts, My version Fogs always ON, Map & Overhead Light Mod,
    Tail is same as Parking. If you connect the negative of an added switch to the beige, it'll dim. If not, then it will just illuminate with "regular" ground.
    upload_2020-8-27_18-4-33.jpg
    Stop is the input to the Break Controller.
     
    Last edited: Aug 27, 2020
    daveeasa likes this.
  12. Aug 29, 2020 at 7:24 AM
    #12
    daveeasa

    daveeasa Slowest crimp in the West

    Joined:
    May 14, 2020
    Member:
    #328079
    Messages:
    2,667
    Gender:
    Male
    First Name:
    David
    San Diego
    Vehicle:
    2016 OR 4x4 DCSB MGM 6MT
    Ah, I get it now, trailer harness has undimmed illumination via (+) lead for parking lights. What it doesn’t have is dimmer ground (-) to complete the circuit for dimmed switch illumination. And the beige wire for that is a TBD for me. Makes sense now.

    Since this is 40amp max, what would the relay recommendation be? I could get an 80 amp relay for a safety margin or a 20/30 or a 30/40. I assume I ought to go with the 80 to be safe but not sure if brand matters in terms of quality?

    So it mostly boils down to a question of mounting locations for relay and fuse block.

    With all that said, I am planning on bringing in 4 gauge from the battery for my amplifiers to under the seat so if I were to ignore illumination then I’m not sure the trailer harness buys me all that much extra. Perhaps the biggest reason to use it is that the wire size is already good for a connector to the relay vs a distribution block to reduce the 4 gauge to 12 or 14.
     
  13. Sep 15, 2020 at 10:25 AM
    #13
    daveeasa

    daveeasa Slowest crimp in the West

    Joined:
    May 14, 2020
    Member:
    #328079
    Messages:
    2,667
    Gender:
    Male
    First Name:
    David
    San Diego
    Vehicle:
    2016 OR 4x4 DCSB MGM 6MT
    Just to close out the loop on this if anyone else stumbles on it in the future. Caribe Makaira redirected me to an earlier post on my build thread where he had spelled this out for me. I'm nearly complete and have tested and confirmed all works properly.

    Specifics as follows:

    1. I purchased a Tekonsha brake controller harness. I noticed it had blue and black colors reversed and I wanted a clean setup for this work so I de-pinned everything and re-pinned the blue to match OEM blue so it'd all be blue and removed all other wires from the connector.
    2. Purchased 25' of blue 12 gauge GLX wire to extend to under the cupholders.
    3. Purchased a blue sea maxi fuse holder to install in the driver's kick panel and a blue sea compact 8 circuit fuse block for under the cupholders.
    4. Purchased a Tyco high current relay model 23232 A 0001 X003 to turn brake controller +12V to ignition switched (75amp max)
    5. Recycled the leads from POUTLET2 which fed the center console 12v power connector after removing them from the plastic connector to trigger the relay
    6. Various heat shrink, loom, fuses and two sizes of ring terminals, using the obvious ground, mounted the fuse holders and relay, test fit.

    Using a maxi fuse holder in the driver's kick gives me maximum flexibility if, in the future, I need to add a brake controller. I can simply run a new 12 gauge (or 10) lead from the battery directly via one of the firewall grommets without disruption to the downstream components. It also allows me to join the rather short brake controller harness wire to the longer wire needed to reach the destination location without soldering or crimping and burying that joint inside the dash. So, it's strategic for me but entirely not necessary for anyone else as this circuit already has a fuse upstream.

    NOTE: It is possible to re-pin and tap into the light circuit for power to switches but the Tekonsha doesn't have a lead pinned for that by default. Since I wasn't going to use that harness for actual brake controller duty, the red wire would have worked well for this. I'm planning to tap illumination from the A pillar harness instead so I can get dimmed illumination, leveraging a DSIM T harness for that.

    Photo is prior to final wire routing and zip ties, also I'm still waiting on some ring crimp connectors and that blue GLX wire to complete this.
    usb_power.jpg
     
  14. Sep 15, 2020 at 4:28 PM
    #14
    caribe makaira

    caribe makaira [OP] Well-Known Member

    Joined:
    Feb 13, 2011
    Member:
    #51121
    Messages:
    6,239
    Gender:
    Male
    Caribbean, Puerto Rico
    Vehicle:
    05 PreRunner TRD Offroad AutoTrans
    Hood Struts, My version Fogs always ON, Map & Overhead Light Mod,
    Not a location I'd choose but...

    upload_2020-9-15_19-28-9.jpg
     
    daveeasa likes this.
  15. Sep 15, 2020 at 4:35 PM
    #15
    daveeasa

    daveeasa Slowest crimp in the West

    Joined:
    May 14, 2020
    Member:
    #328079
    Messages:
    2,667
    Gender:
    Male
    First Name:
    David
    San Diego
    Vehicle:
    2016 OR 4x4 DCSB MGM 6MT
    Where would you want this stuff? Somewhere where the fuses would be more accessible? Or somewhere less prone to accidental short?

    Thanks for the suggestion on insulating, I wonder how best to do that with this relay and still allow disassembly without cutting. Seems like a slide-on boot would be best.
     
  16. Sep 15, 2020 at 5:20 PM
    #16
    caribe makaira

    caribe makaira [OP] Well-Known Member

    Joined:
    Feb 13, 2011
    Member:
    #51121
    Messages:
    6,239
    Gender:
    Male
    Caribbean, Puerto Rico
    Vehicle:
    05 PreRunner TRD Offroad AutoTrans
    Hood Struts, My version Fogs always ON, Map & Overhead Light Mod,
    Boot would be great, tight.
    Location would've been near the other fuse panel in the cab..Driver Kick panel.
     
  17. Nov 5, 2020 at 8:51 AM
    #17
    RX1cobra

    RX1cobra Well-Known Member

    Joined:
    May 20, 2019
    Member:
    #293789
    Messages:
    1,130
    Gender:
    Male
    Vehicle:
    19 OR
    I'm planning to use this as power for a heated seat install. I had to repin the plug. Does this look right? Black is ground, blue is power and white is illumination for the switches?

    The power and illumination will be run through a simple fuse box for a clean install. Should also leave me an extra constant 12v source (each seat will have it's own fuse and one for illumination). I plan to grab a switch 12V from the fuse panel. https://www.dormanproducts.com/p-16556-85668.aspx

    Trailer plug 1.jpg Trailer plug 2.jpg
     
  18. Nov 5, 2020 at 9:04 AM
    #18
    daveeasa

    daveeasa Slowest crimp in the West

    Joined:
    May 14, 2020
    Member:
    #328079
    Messages:
    2,667
    Gender:
    Male
    First Name:
    David
    San Diego
    Vehicle:
    2016 OR 4x4 DCSB MGM 6MT
    So, on my Tekonsha, blue and black were reversed vs the colors Caribe used in his diagram. I'm not sure if mine was a one-off goof though.

    The black is not ground. Ground is pin 5 and on the Tekonsha it was white with an extra ring terminal. If yours was a Tekonsha too and you've re-pinned and swapped blue and black then it looks like you are set on +12v and parking lights but the black wire in pin 7 is not ground and you want to either de-pin or tape/heat shrink it off. Since it looks like you've already shuffled I would de-pin.

    The ground from the factory harness is tiny and not worth tapping into IMHO, better to use a ring terminal to vehicle chassis than go through the connector to what looks like 22 gauge or at best 20 gauge.
     
  19. Nov 5, 2020 at 9:11 AM
    #19
    RX1cobra

    RX1cobra Well-Known Member

    Joined:
    May 20, 2019
    Member:
    #293789
    Messages:
    1,130
    Gender:
    Male
    Vehicle:
    19 OR
    Ah, thanks. I see that now looking at the first post (what I get for "working" and doing this at the same time). I just looked a the bottom pic and saw both 5 & 7 as black and thought both were ground. I went with 7 for exactly what you're saying. 5 wiring gauge was too thin for my liking. I removed pin 7 and will use 8 for power and 3 for lights. I'll ground to the chassis.

    Too bad there's no switched 12v on here.
     
  20. Nov 5, 2020 at 9:23 AM
    #20
    daveeasa

    daveeasa Slowest crimp in the West

    Joined:
    May 14, 2020
    Member:
    #328079
    Messages:
    2,667
    Gender:
    Male
    First Name:
    David
    San Diego
    Vehicle:
    2016 OR 4x4 DCSB MGM 6MT
    Agreed would be nice to have switched power too.

    I have an extra high current relay which I'm not sure I'm going to use quite yet but I _might_ try to use it for switched power in the bed down the road.

    I think the only useful pins in this connector for aux switches/fuses are +12v and parking lights. I was actually working on my heated seat switches last night/this morning and I'm pretty close to adding the parking light tap for them, should have just done that up front.
     

Products Discussed in

To Top