Rear Turn Signal Resistor Harness

Posting this up for anyone that has the same OCD as me when it comes to vehicle wiring.

Unlike the front turn signals, there aren't any LED bulbs (to my knowledge) that integrate a resistor for the rear turn signal bulbs. In other words, for the rear turn signals you must use a resistor in order to prevent hyperflash.

Now the problem I have with adding resistors is typically installation requires a scotchlok connector or t-tap connector. Personally I hate both of these solutions because they damage the insulation on the factory harness and are generally just not that great.

So I built a "patch harness" that allows me to connect a VLED VLR-6 without doing any permanent changes to the truck's wiring. The picture is of the almost finished harness, I am terrible about remembering to take pictures once I start working on something. Last step was adding some looming to protect the wires. Basically this plugs in between the taillight and the harness on the truck to add the resistor without any cutting, splicing, etc. Some of you may think this is unnecessary, but for it was well worth the minimal cost and time to preserve the integrity of the factory wiring.

For anyone interested in doing something similar. Please be aware that this requires some skill in soldering or a $400+ crimp tool. Obviously, you can use any resistor you like and there are different ways of incorporating it into the patch harness. I ended up making mine like this based on the components I had on hand from a VLED order.

https://www.corsa-technic.com/item.php?item_id=747
https://www.corsa-technic.com/item.php?item_id=1044
https://www.corsa-technic.com/item.php?item_id=429

 

I wish I knew this a couple of months ago when I installed mine. I'm not fond of those crimping splices either.

 

This is exactly what I wanted to do. Do you mind sharing with me what your order looked like so I can see each part number for wires, seals etc. Thanks so much.

 

I have been considering doing the exact same thing, but just hadn't gone far enough to sort out what connectors I needed yet. So thank you for that!
I've got a crimping tool that cost way less than $400 for doing these terminals.
Now I've got to decide what to use for resistors - the cheap ones that came with my Auxito front signal bulbs (that I didn't need to use), or buy a set of the VLED ones. The VLED ones come with the disconnect plug, but I could also build one of those using these connectors just as easily...

 

How much for a set and ship to 85286?

 

I just ordered everything up for $28 shipped from CORSA-Technic. I also ordered the VLED resistors for $30 for (2) 6 ohm with duo-tap connectors which will cut off the ends of duo-tap and solder in place. I already have their red LED 921 bulbs. I will let everyone know how it goes.

 

Interesting... What year is your truck?

So I went with the Diode Dynamics XP80 LEDs for all the rear lighting (stop/tail, turn, and reverse) as well as front turn signals on my '21; and didn't have to add resistors. For comparison, on my girlfriend's '21 Tacoma, we used the same bulbs and did have to add resistors.

 

Nice. I made a harness very similar to this back when I installed VLEDs in the truck, after figuring out that replacing the wiring harness to the rear tail lights meant replacing the harness all the way back up to the front (basically requires removing the bed and cab from the frame)

 

I made the same harnesses last June. I avoid hacking oem wires whenever possible

 

The connectors include the pins and boots. You just have to select the right size based on the gauge of wire you are using. I used 16AWG so I went with the middle size for the pins and boots.

Any resistor sold for correcting hyperflash should be good. I think the VLR-6 I used is 25W, which is common for these applications. As far as connecting it to the harness, I wouldn't say the connector helps any. You could easily solder it into the middle of the harness or use butt splice connectors.

Yeah, the only crimp tools I have wouldn't work. The $400 tool is what they recommend for these, but I am sure there are others that would work, I just didn't care enough to find one and buy it. I'll have to get a nice one eventually for working on my track car.

I am not planning on making these to sell. Sorry.

It should work fine for you, just make sure you confirm the polarity before putting the taillight housing back in place. If you have any questions, post them up.

Mine is a '20 Platinum. I would guess that the bulbs you are using had enough resistance to properly load the circuit in your Tundra. I am using the VLEDs linked below and had hyperflash without the resistors.

https://www.vleds.com/shop-bulb-numbers/921-led/921-6-r.html

 

I’ve got the connectors coming. I think I’ll just solder the resistors I have right into the harness for simplicity.

The crimper I have is the Hozan P-706 shown here:

$37 Hozan Crimping Tool (For Open Barrel Type Contact) Crimping Pliers Die Part with Steps, Thin Finish AWG #28 - #14 P-706

https://www.amazon.com/Hozan-P-706-Open-Barrel-Crimper/dp/B002TKG11G

 

Let me know how that crimper you have works for these. I'm curious as its a different design from what you typically see.

 

I’ve been using it for doing connectors like these since 2015. I just did my OEM LED bed lights using it on the same style of connectors (Yazaki 090 waterproof) to modify the harness that came with them to tap in an extra switch in the bed and route that down to the same plug as the one light.

It takes a little finesse to get used to doing the really small connectors (22 and 24 AWG like the AMP 025 connectors), but it’s got separate round “crimp” spots for different insulation sizes and those work great on the waterproof seals too.

 

Well I just ordered one....

Thanks for the recommendation!

 

Thank you. When you say polarity, isn’t it just a two wire harness which will allow the resistor wires be installed in either order? Or did you mean to line the wires in the pins correctly in each side? Thanks for your help.

 

Most of the LED bulbs have polarity. If you put it into the bulb socket and it doesn’t work like it should, pull it out and turn it 180 and then test it. It’s best to do that before you actually put the whole taillight assembly back into the truck.

 

ahh, completely makes sense, thank you!

 

Do you have a link for the rear turn signal bulb?

 

Thanks for posting. Nice to know where to find those connectors as I'm planning on making tail lights soon..... maybe.

 

https://www.diodedynamics.com/rear-turn-signal-leds-for-2014-2021-toyota-tundra-pair.html

 

Ironically enough, this morning I had the hyperflash, only on one side, and only for about 10-15 total flashes, then back to normal...

 

Great info here

 

Was that with the LED bulb? I have had this happen on my 100 series with halogen bulb that was nearing the end of its life. With an LED the only thing I could think of is it was cold, thus lowering the resistance. After 10-15 flashes the temperature went up enough to raise the resistance enough for the truck to not have hyperflash. Another possibility would be a slightly loose connection.

 

It was with the LED, and it definitely wasn't the coldest temps I've used a turn signal, nor was it the first set of flashes... Either way, I'm chalking it up to an anomaly or slightly loose connection