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.
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.
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.
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.
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.
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.
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.