Introduction: How to Install Load Resistors for LED Turn Signal Lights

Why are installing load resistors necessary for LED turn signal lights? If you don't install load resistors (also known as equalizers) with LED turn signal bulbs, you will experience the notorious hyper flash issue. Hyper flash is exactly what it sounds like, where the turn signal light flashes rapidly and is almost headache inducing. Not only is this ugly, but you may also attract the police who think your bulb is burned out. This sounds completely unnecessary and a huge hassle to boot.

You will need 50W 6 OHM load resistors and tap the load resistor to the stock harness in parallel. Load resistors also have no negative or positive, making it easier for you because you wouldn't have to worry about which wires goes to which side.

Step 1:

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1156, 3156, 7440 are single filament applications so there are only two wires (one positive, one negative). This is very straightforward as you need to simply tap the load resistor wires between the two wires.

Step 2:

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1157, 3157, and 7443 are double filament applications which have three wires (one shared negative, one positive dim mode, and one positive brighter/blinker mode.) There is a little more trial and error involved with the wiring. We recommend you tap the load resistor between the most vivid wire color (usually the brighter/blinker) and the least wire color (usually negative). In this tutorial, we are going to try to tap the resistor the red and black wires.

Step 3:

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Test the turn after the wires are tapped. If the turn signal still hyper flashes, take the wires out and tap it to another wire and try again. The most times you will try to tap the wires is three times. We are going to assign each wire with a letter for easier reference: Red-A, Green-B, and Black-C. We originally tried A and C and tested it to see if it works. If not, try and C. If that still doesn't work, try A and B.

Step 4:

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If you have tried all three ways and the hyper flash issue is still there, then perhaps the issue causing this is the connection. Many people install load resistors with a T-tap because it sounds easy, but we definitely don't recommend this route. T-taps are sometimes unable to cut through wire and causes a loose connection or intermittent function. We recommend you directly merge the load resistor to the stock harness. Actually, my professional stereo installations have installers merge the wires instead of using T-taps.

Step 5:

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How to merge the wires: We recommend you use a wire stripper to expose the copper wire in a small slit without damaging anything. If you don't have a wire stripper, you can also scrape through the plastic using a knife or scissors. Don't forget to use electrical tape to cover it after you connect the wires. An awesome thing about merging wires is that they have a 100% success rate every time. You won't have that intermittent working/not working issue like the T-taps. Don't forget to mount the load resistor to the metal using zip-ties and not double-tape.

Step 6:


1. Merge wire instead of using T-taps for a perfect connection.

2. Always try different wire combinations for double-filament bulbs.

3. Mount the resistor to metal so you can prevent heat damage.


SteveJ151 (author)2017-06-09

I hae tried all a,d still not working,

EstebanS37 (author)2017-06-09

Will these instructions still apply when using LED Brake replacements for a 7443?

noproblemo (author)2017-04-14

I'm wondering if anyone has tried using a 6 ohm 1 watt or 5 watt resistor instead of a 50 watt resistor. With these small bayonet bulbs, the current draw can't be much, so why put a $3-5 50 watt resistor there? Let the resistor wattage match whatever wattage the bulb draw is. Isn't the 50 watt a bit overkill in these places? I'd rather buy a box of 5 watt resistors, not the fancy looking gold ones.

DavidM1426 (author)noproblemo2017-05-29

The 7443 bulb as an example has a 25 watt blink filament. It is using 25 watts when it is on so it is drawing about 2.25 amps - quite a bit of current actually. The power in the resistor is about 30 watts when it is on. It is on half the time, so the average power is 15 watts. A 1 or 5 watt resistor would fail right away unfortunately.

BrianT59 (author)2015-12-17

I have one 3157 bulb turn signal. If I wanted to tap into the turn signal wire for a second bulb when I convert to led's, would I need two resistors for the same circuit? Or would I put one resistor in before I splice in the second plug will two led's work with just the 1 resistor or will it overload it?

ilovejdmtoy (author)BrianT592015-12-29

Hi, you'll need one resistor per each LED turn signal bulb

LeviM33 (author)ilovejdmtoy2017-01-21

Hey I'm wondering if I can get your help on wiring up my resistors to my 02 ram.

LeviM33 (author)LeviM332017-01-21

Idk if I could send pics on this thing or what. But I've been reading these posts and you seem to know what you're doing. Maybe I can text you pics of what I'm trying to do?

fourblades (author)2016-12-05

I've done this and will be switching out of T-taps. My only question is does the resistor matter where it would be mounted? Should it be screwed/tied/taped? I've used this item to take care of LED hyper flashing but I may need to diagnose another issue.

Thunderbird™ (author)2016-07-14

I have a 1997 Jeep Wrangler TJ. I’ve had stock-looking LED brake lights already installed for some time now. They work fine. Recently, I replaced the two front turn signals with LEDs and I’m having problems. Both sides blink fast now. Even my dashboard lights blink when turn signal is operating. I know resistors are a necessity for such a product. I’m unsure what is causing the problem. Any help would be most appreciated. These are the LEDs I installed recently.

It's because the flasher unit that makes your bulbs flash requires a certain load, most flashers use a bi-metal switch and not a timer the bi-metal without enough load does not get hot enough to flex properly and therefore the flasher unit flashes too fast. You can buy flasher units that work on a timer and are suited for led's but matching one to your vehicle may be too much of a pain.

ve3vxy (author)FrederickJ72016-11-29

I also have a jeep TJ please note that the flasher is internal to the switch and is not replaceable also its electronic not bi metal

ivan97 (author)2016-11-11

I installed resistors my 06 impala and took them off because i believe i broke resistor, now turner signal wont blink. it just stays on, anyone know the problem?

ChristianR110 (author)2016-08-05

OK so i have a Honda Accord and wanted to upgrade turn signals to leds. The rear I bought the plug and play resistors and fixed the hyperflash. Now I want leds in the front and it is hyper flashing due to the new leds in the front. Bought some plug and play resistor. Worked fine without headlights, but as soon as i turned on my headlights and used the turn signal, it would hyperflash. The new plug and play resistors I took apart and followed your instructions and tried it the 3 different ways mentioned. None worked. I'm really frustrated right now. please help

JeremyL82 (author)2016-05-06

Has anyone tried getting a potentiometer rated for 50 watts? Seems like you should be able to adjust the resistance until you find the desired flash speed.

BenC127 (author)JeremyL822016-06-08

Same thing can be accomplished with a capacitor assuming that the flasher is a RC Time Constant circuit. I would be more concerned with the ohms vs the wattage of the resistor. You could probably get away with 25W but no lower due to heat, 6ohms is baseline for the resistance.

KevinG75 (author)2016-01-03

I have a 97 dodge with 3157 blinkers I put the led bulbs in it. In the front with load resistors. Every time I use my blinkers all my lights flash like my hazards are on. Any suggestions how to fix?

DavidP401 (author)KevinG752016-04-16

Might be in backwards. Try turning it over the other way.

BenC127 (author)DavidP4012016-06-08

All Resistors with the exception of Potentiometers or variable resistors have no polarity, they can't be installed backwards either way works the same.

Bobbing (author)KevinG752016-05-21

+KevingG75 Use an Electronic Flasher EP27

ChaseT6 (author)2016-03-30

installing led turn signals on the rear of my 97 Harley fatboy, with load resistors... when hazards on they flash with just turn signal on its a running light???? have wired it up 1000 different ways what am I missing????

djinstruct (author)2016-01-23

I just finished completely rewiring my 1948 Willy's Jeep. Upgraded stop, tail and turn lights to LED with new electronic flasher. Installed a turn signal switch by Grote to integrate turn and brake light functions. Charged the battery to 12.6 volts. Now when I test, all systems work fine when operated individually. Also, Brake light works together with either head/tail lights, or when turn lights are on. Problem is, turn lights will not operate when head/tail lights are on at the same time. If the turn signals are on, and I turn on the tail lights, then the turn signals stop. If the tail lights are on, then the turn signals simply will not come on. I have confirmed that each light fixture is wired correctly. The head/tail light circuit is completely separate from the turn and brake light circuits (different fuses and wires). From reading the posts below, the electronic flasher should allow the system to work without wiring in load resistors. Any ideas? Thanks.

MarvinE5 (author)2016-01-17

I have a 97 ford explorer. Changed brake/tail lights (one 3157 bulb) to led. They work properly but info center is throwing lamp out on both circuits. Have resistors but still not sure how to wire in. Have green wire for brake. Brown wire for turn and a ground. Any ideas ?

NeoPDX (author)2016-01-15

Hello, so I own a 2011 Nissan Altima Sedan.

I bought ASTAR 3157 LED Switchbacks for the front. And 3056's for the rear.

Obviously, 3157 (two filaments for daytime running and Turn) 3056 (Single)

I knew to buy 6ohm 50watt Resistors for each light bulb I am changing over to. So, I started with the rear tail lights first and added the LEDs then the resistors. Then I changed out the fronts with resistors as well... Needless to say, I tested out the results.

The drivers side: Lights in the OFF position, Just using turn signals~~> Slow Normal Flash.

Then testing the passenger side: Lights in the OFF, Same~~> Slow Normal


So then switched over to DAYTIME running: Drivers side~~> HYPERSPEED

Passenger Side~~> Normal Slow.

What gives?

Should I use thicker gauge wire?

Is there a distance that the resistor needs to be from the bulb?

David Anderson

Portland, OR

ThomasT7 (author)2016-01-07

No theory? What's the final resistance of the parallel circuit with the led bulb and load resistor? What vehicle is the 6 ohm load resistor compatible with? I ask because my bike uses old high-resistance bulbs, about 0.5 ohms each, and with the newer 0.1 ohm turn signal it not only clicks very rapidly, but the light doesn't even have enough time to "heat up" and glow. I think I need to put 0.4 ohms in series instead of parallel or something, but who knows.

D1bell (author)2016-01-05

I am installing front LED turn signals in a 1998 Trans Am which uses the 3157 bulb. I have merged the positive side wires with one side of the resistor and connected the other side of the resistor to the body. I am still having issues with slow or no flash instead of hyper-flash. Would connecting directly to the body be the cause of this. The light socket is very difficult to reach without removing either a underbody panel or the headlight assembly which is the reason for connecting directly to the body.for a ground. Thanks.

Jeffro bodeen (author)2016-01-01

I have blue led turn signals for my mirrors I installed the left works fine but the right don't work at all the wire color is blue red and black do I just need a load resistor for this and how many Watts and ohms

ClarenceS4 (author)2015-12-09

I have 2008 ford ranger. Put back led turn signals. Flashed fast. Now I put led turn signals in the front , now they don't flash at all. Will load resisters help with this problem?

KirkW9 (author)ClarenceS42015-12-10

Flip them over. LEDs are polarity sensitive. You've got a 50% chance of installing them backwards. Pull them out, flip, and reinstall them in the connector and see if that works

RandyR14 (author)2015-10-29

Will load resistors work for the issue I'm having? I've purchased a couple of different brands of led taillight bulbs for my 2015 Tundra and have had the same results. They are the 3157 bulbs. I put them in the socket one way, the brake lights work but no taillights. I turn them around in the socket, the taillights work but no brake light. Any advice?

Jasond41 (author)RandyR142015-11-07

I had this same problem with a 2003 ford falcon and I put a 50w 6ohm load resistor on one side of the tail light wiring and fixed the problem. Only one is needed on the tail circuit so either side would work.

MauriceY1 (author)2015-04-02

My issue with the tail light/turn signal is that when I turn on the lights, the LED is really dim. Once I step on the brakes the bulb is nice and bright. Will the load resistor help in this situation? If so, how would i tap one side of the resistor to the tail/park wire? Oh, I have the LED blub installed on my a travel trailer not a vehicle.

DavidS295 (author)MauriceY12015-10-17

How many lead wires to led? If just 2 (12vdc+ and 12vdc-) make sure no resistors in line with bulb. Follow my instructions in previous post... Make sure to use no bigger values for diodes (6w) and stay around 300/400 ohm for resister. Tail light should end up with no less than about 50% of what brake light is.
Sounds like you resister in tail light circuit is to high a value...
Install in this order from power source towards bulb... Resister/diode
Line sides of both diodes and 12v+ wire from bulb soldered as one joint! Make sure diode with resister is soldered to only tail light source (connected at open end of resister) Brake wire lead solders to open end of other diode...

TylerA11 (author)MauriceY12015-09-22

Same problem... Cant figure it out. In chvy astro. Front leds basicaly not functioning while the running lights are on but works properly once engaged in turn signal mode switch back LEDs plz hlp

ilovejdmtoy (author)MauriceY12015-04-03

From what you described, it actually seems normal. The LED light for the tail light/brake light would have two features: dimming mode for tail lights and bright mode for brakes.

MauriceY1 (author)ilovejdmtoy2015-04-03

When I say dim, you can barely see it is at night. I guess I would have to take a picture of it.

DavidS295 (author)2015-10-17

Rember... To label each wire from original circuit as you remove them. Diagrams help so does a DC volt meter to insure each wire in harness is correct. If not sure... Test!
My labels were done on computer, then covered with clear tape. I also clipped the ires on my diode/resister packet soldered and covered these joints with shrink tubing. Easy to id input (3 wires) output (2 wires) easy to strip shink tube off and desolder to remove...
Again... Enjoy looks and works nice!!!

DavidS295 (author)2015-10-17

Rember... To label each wire from original circuit as you remove them. Diagrams help so does a DC volt meter to insure each wire in harness is correct. If not sure... Test!
My labels were done on computer, then covered with clear tape. I also clipped the ires on my diode/resister packet soldered and covered these joints with shrink tubing. Easy to id input (3 wires) output (2 wires) easy to strip shink tube off and desolder to remove...
Again... Enjoy looks and works nice!!!

DavidS295 (author)2015-10-17

I have custom motorcycle and want to install LED's for turn lights. Which way is better to install load resisters...
1. At each bulb using 4
2. Since I can get to flasher using 1 here
I did a tailight/brake light combo using 12v strip lights. Cut strip lights in set of 3, to length of 3 sets (9 bulbs). Used hole punch to get paper circles and a dab of elmers glue on each to cover all nine led's. Mounted to where I wanted it with the double sided tape that came attached to strip and let (in my case) fender sit in sun to let strip soften.
Then I located (alread labeled) tail light wire and brake light wires. Using 2 - 6w diodes and a 400 ohm resister I soldered a circuit.I soldered the 2 diodes with the line marking and 12v + wire together. Soldered the other wire from to my 12v - wire. To one of the diodes I soldered my resister.
Now all I have left (2) is my 12v + wires from tail light and brake circuits. Solder tail light 12v + wire to diode/resister circuit (open end of resister). This will give you low power for tail light. Soldervbrake 12v + wireb to open end of other diode. This will give you high power for brake light.
For information this is single element LED's, the diodes keep voltage from migrating up opposite circuits. When I was done I covered complete mix with the use of my glue gun. I had used vaseoline to coat a small 11/2 x 1 1/2 box, cutting 5 slits after glue hardened inserted glob into box, with wires in slits I suspended mix in center, then fill box with glue. After in hardened peeled box off. Result was a waterproof 1 1/2 x 1 1/2 x 3/4 inch box. No heat so could zip tie it anywhere. If I need to remove at later date, all I need to do is snip wires.. Leaving short leads on circuit box and wires color coated, I labled each beforehand so future ID is easy.
You now have single bulb (2 wire) or strip bulb LED brake / tail light circuit. Only thing left was to use superglue gel to fill edges of LED strip lights to mounting as I was not sure how good the double sided mounting tape would be exposed to the elements. Then having previously covered each LED bulb I primered and painted everything, when dry peeled of the paper covers... Turned key on and.... Tail light!! Squeezed brake lever...
Brake light!!!

MacJ2 (author)2015-07-27

You don't just randomly tap into wires, even from a light bulb. That's ludicrous. Either locate the turn signal and ground wires via online lookup, or with a simple volt meter. And then tap the negative and turn signal wires to the resistor.

Where did you people come up with the idea that the brightest color wire is the correct wire for the positive and the negative?

On one of my vehicles the front turn signals are light blue and dark blue (depending on side), for rear it is yellow or green (depending on side).

if you don't know how to tell people how to connect something logically, don't do it, Someone could get hurt or short out a circuit as in jumping two positives together.

And also, you might want to tell people to mount these resistors away from painted metal or plastic since they can get very hot during extended periods of use. For example, leaving the hazards on for quite a while could get them hot enough to heat the metal on a fender enough to start to melt the paint on the other side.

Don't believe me, leave then on for fifteen minutes and touch one, after you scream, you will understand what I'm saying.

Remember, these resistors are taking the amperage to heat up just like a standard incandescent light bulb. So they are getting as hot as the filaments inside the bulbs that light up from HEAT!

belangers (author)MacJ22015-09-08

never rely on the color codes from any chart. Always test it with a digital meter. Not doing so is a great way to tag an airbag wire that isn't covered in a yellow wireloom and getting blasted with an airbag if the color is wrong. Never use a test lamp either, they are notrious for setting airbags off because it triggers them with a ground signal. Test lamps are not good to use on digital circuits either, especially with new can-bus data bus systems. Use your heads and never go by brightest color, or, by a chart that some knucklehead posted as wrong online because they think they know. Pinouts are wrong 50% of the time and I have seen several of the same car's diagram have different colors and pinouts from amphenol connectors online just about daily.

If you want , use the colors from a chart to guide you with the tester, and, always test your tester before you begin. Not doing so can lead to big problems, especially if you rewire the probes for amperage readings and never put them back in place for a voltage reading.

I've been wiring and troubleshooting vehicles for 35 years and my last mistake was when I was 17 years old, and, it was a costly one. It's the best way to learn a lesson, the hard way, but, it won't bring you more business once you smoke something burner that isn't yours. I completely agree with customers that it is the installer's fault if mistakes are made. They could all be completely prevented if you take the time and effort to test all of your connections. Also, before you wire anything, be sure you know exactly how to read circuitry and operate a meter... All circuits and tests performed for specific circuits are not created equal.

NickP7 (author)2015-06-08

Hi guys, need to check with u if I need to install all blinkers means left and right each a load resistor to ensure it's correct blinking rate? For headlight & tail light doesn't require one load resistor right?

MacJ2 (author)NickP72015-07-27

EACH light bulb requires one 6W resistor.

belangers (author)MacJ22015-09-08

No, each bulb requires one 6 ohm, 50 watt resistor, not 6 watt.. :-)

Fredric72 (author)2015-06-14

Hello, installed ledturnlights on my Lincoln Town Car 1999, with load resistors. It works fine when testing with key turned and the engine shut off. When running the engine, the turn signal flashes at normal speed the first four or fine flashes, but then all of a sudden speeds up like there were no resistors? Anyone knows what's wrong here?

MacJ2 (author)Fredric722015-07-27

Bad resistor. Heating up and internal circuit is failing due to the heat.

TomV7 (author)2015-05-25

Infinite7 (author)2015-04-26

I have a small problem and need a little guidance. I just recently bought an integrated sequential tail light for my 2008 R1, offline, and it came from china with no wiring instructions and i dont know how to wire it up properly. The harness is plug in play but the 2 yellow wires have no harness and the harness for the bike are 2 wire. Can anyone help?

Infinite7 (author)Infinite7 2015-05-07

I figured it out. Thanks anyway

william.lynn.779 (author)2015-04-05

Have 2004 Suzuki SV1000S. Installed front and back LEDs w/ integrated tail lights. Bought LED Flasher Relay thinking it would fix problem but did not. Should I replaced Relay with original relay and get load line resistors to regulate voltage?

About This Instructable




Bio: Everything about automotive LED lights
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