DIY License Plate Light Disable-In-Reverse Harness (DIR)

This thread is a cumulative info thread on how to enable a defeat of the license plate lights when a 3rd gen Tacoma is in reverse.

Credit to @caribe makaira and @Puppypunter for the design, prototypes, and tireless effort to make this truly incredible mod a reality.

This is not a BST thread, nothing is for sale in this thread.

• As of 2/11/2021 I have a 3rd Gen BST thread for anyone who wishes to purchase a harness for a 3rd gen.
• As of 6/24/2021 I also have a 2nd Gen BST thread.

This thread is for anyone wishing to DIY. Please try to keep the discussion limited to how to do things, what parts to purchase, where to buy them, and which tools to use.

This may not technically be a legal modification for street use. Additionally, the OP and any named or unnamed contributors to this thread assume no liability for potential damage to anyone's vehicle by following any of these instructions.

With that out of the way, here is the diagram, courtesy of @caribe makaira


Here is a picture of my rear camera via my Pioneer head unit with parking lights on but not in reverse, hence the license plate lights are active. NOTE that this is with Diode Dynamics HP3 5000k license plate bulbs.


And here is a picture of my rear camera when in reverse (NOTE this is with MESO total tail stage 1 reverse switchback bulbs which are quite bright, significantly brighter than stock halogen reverse bulbs)


The design is a P&P harness with a sealed relay. The relay mounts to the lower stud in the taillight cavity:


The harness then feeds down alongside the factory harness (photo is before zip ties installed):


And T's into the license plate light OEM connector which then feeds the two bulbs on each side of the license plate:


Parts sheet:

^^ NOTE: The above was done before the design evolved to ensure support for BSM as the original development was done on trucks without BSM. Refer to full parts list below for the most accurate information. The sumitomo plugs are thus no longer needed but 2 additional male and female sumitomo ts-090 pin terminals and seals for 18 gauge are needed.

Full Parts List:

1. Sealed Relay SPDT {relay, mounting bracket, waterproof case, metripack pins and seals for both 18 gauge and 22 gauge} ** NOTE SPST relay will not work for this **
2. Stainless washer and lock nut, m6 x 1.0
3. License plate light T connectors {90980-10942 (Female), 90980-10941 (Male)}
4. Reverse light T {90980-11162 (Female), 90980-11168 (Male)}
5. 1/4" flex loom OR vinyl tubing OR expandable braided tubing sleeve (if you are OCD you can use braided sleeve inside vinyl tube inside flex loom)
6. Inline Tube Replacement for 2 Rolls Factory Electrical Non Adhesive Wiring Harness Friction Tape OEM (J-10-9)
   Friction tape if using flex loom (OP recommended)
7. Zip ties
8. Sumitomo Male and female 090/2.3II pins and seals for TS 090II. The license plate connector needs 4 male/female pin pairs and seals while the reverse connector needs 2. You want to use a 14 gauge terminal when crimping two wires together to form the T portion and 18 gauge otherwise. You won't ever be crimping 22 gauge leads to an 090II terminal, only 18 gauge or 18 + 22. The 22 will feed the relay for signal. The corsa kits can be ordered with specific pin sizes so you want the reverse male or female in 14 gauge pins and seals and all others in 18 gauge. The 14 gauge seals are grey SL4's, the 18 gauge seals are green SL2's
9. Plugs if you have no BSM and don't want to pin all 4 connectors in the license plate T.
10. 18 gauge GXL wire for lighting power/ground (you can use TXL instead, but OP prefers white with black stripe for grounds and striped wire is difficult to find in TXL)
    1. Found white w black stripe TXLin 18 gauge
11. 18 or 22 gauge TXL wire for signal power/ground (if using 18 gauge for everything you want 14 gauge 090II terminals to get 2x18 into a single crimp and note this is a more challenging crimp than 18 + 22)
12. Waterproof crimper
    1. $33 iCrimp Weather Pack Crimp Tool for AWG 24-14 Crimping Delphi APTIV Weather Pack Terminals or Metri-Pack Connectors- Crimp Terminals and Seal In ONE Cycle with Locator & Removal Extraction Tool
       IWISS Weather Pack Crimp Tool (recommended)
    2. Qibaok Weather Pack Crimper Tools Waterproof Connectors Crimping Tool for Delphi Packard Weather Pack Terminals or Metri-Pack Connectors
       Qibaok Weather Pack Crimp Tool (cheaper)

Specifications:

1. 30” wire from relay to the license plate T connector
2. 3" wire for the pass through portion of a T connector

Alternate relay option:
Delphi 630, probably right at the $10 mark, a little bigger, but not terrible.
Mini Relay Connector 75612, 5 Pin, Harness Mount | Waytek (waytekwire.com) $2.75
Hella 7794327 Skirted Mini Relay, 20/40A, 12V, SPDT | Waytek (waytekwire.com) $4.60
Hella 960975007 Mounting Bracket for Relay 75601 | Waytek (waytekwire.com) $0.86
Aptiv 12020156 630 Series Metri-Pack Female 20-18 GA Terminal | Waytek (waytekwire.com) $0.27 X 4 = $1.08

So $9.29 for the relay, no wire.

Additional references for improved reverse lighting:

1. MESO Total Tail Light Kit
2. Drop in Baja Hitch reverse light
3. HIR 921 reverse bulb mod

 

A lot of those pictures appear broken by the way.

 

Thanks, sorry, forgot copy and paste doesn't work on images, fixing.

Better?

 

Pay attention to the clarity and brightness between the two pictures. Top has license plate lights on, dimming the backup camera image. Next shows the difference when the licence plate lights are off.

 

I like the concept. Certainly helps rear visibility. Gotta study this issue as I get used to my new 3rd Gen.

 

Subbed to see if these are produced for sale at a layer point. The new LEDs I just added make it terribly hard to see in reverse at night now

 

Nice work!

I do need to do this.

 

Make another and come install it and I’ll give you $20 lol

 

This is awesome! If you ever wanna sell these I'll be one of your first customers. Those plate lights drive me crazy at night and I haven't come up with a way to shield the top of them from the view of the camera that wouldn't look awful but this is so much better.

 

Some notes:

1. Self install and it’s trivial. Two 10mm bolts for driver side taillight. Bolt on relay. Connect T for reverse. Feed harness down alongside OEM and zip tie in place. T license plate connector and test. The final part is on your back under the rear bumper. 5-10 minutes if you are quick, 20 max if you are turtle speed.

2. Working on options to produce these. The crimping and tape/loom assembly time isn’t bad for someone to do themselves but it’d be nice to have the bulk work done at scale by machines.

3. PNP reverse tap is a nice bonus since it’s right where you want it. Soft topper brake tap could potentially be an option as well but that’s 2 more connectors and more wire. So the final design for any bulk production is perhaps still mid refinement to maximize ROI.

4. connectors aren’t cheap in small quantities. People may not realize that, I know I didn’t. They can be up to $4 each. So at $10-$20 for the waterproof relay the raw parts cost is well over $20. Probably close to $50 right now for a run of 50/100 units. I’ll see if I can put together a reasonably comprehensive parts list with pricing sometime in the near future.

5. The biggest drawback to DIY the harness is that you need a weatherproof crimper. They don’t need to be expensive but it’s not something most people want to buy for one time use. Also ordering everything yourself with shipping and minimums makes the total well over $100 which is rather silly money to spend for something like this if you’re not already interested in other similar projects.

For now this us purely an info thread. If a purchase option becomes a possibility I will make sure that is clear in the thread and first post.

 

If you start a list, please put me on it.

I will keep an eye out.

 

Same!

 

I'm also interested if this happens. Especially with a reverse tap for something like this:

https://www.tacomaworld.com/threads/drop-in-baja-hitch-reverse-light.674339/

 

I'm running something similar:
https://www.tacomaworld.com/threads/back-up-light-installation-link-and-bs-thread.569289/

This is mainly because I have Prototype harnesses for the Total Tail, but have stuck with incandescents for the turns.

Based on mine, that @MESO drop in will be killer.


Edit: I just saw that you posted there.

 

Production Plug-n-play for the win!

 

Just a thought, but maybe accessorides.com could help produce these more cheaply? I remember them making harnesses for someone else’s idea in a similar thread a while back.

 

If you make plug-n-play, I would go for two. One for our 2019 and one for our 2021.

 

Another relay & cover option.

Bussmann CFH Waterproof ATM Fuse Ultra-Micro Relay Holder 12V with Terminals

https://www.amazon.com/Bussmann-Wat...1a3b8&pd_rd_wg=8LTpQ&pd_rd_i=B076FFZVTF&psc=1

 

Another good source for some of these connectors i.e. 90980-11168 (Male) is https://www.corsa-technic.com/