Why Do LED Turn Signal Bulbs Need a Resistor?

LED (Light-Emitting Diode) bulbs are a very popular pick amongst drivers of many different kinds of vehicles. They are longer-lasting, brighter, and more energy-efficient than factory-grade, stock Halogen bulbs, which tend to dull and grow dimmer over time.

Although LED bulbs may seem more expensive initially, they more than make up for their cost by the need to change them much less frequently than their outdated predecessors.

When it comes to turn signal bulbs, LED models need a resistor (or flash controller) in order to function properly and at their maximum efficiency. One LED resistor is needed for each turn signal bulb.

Many LED turn signal bulb models feature built-in resistors to make the upgrade a seamless one.

Stock incandescent bulbs drain more energy from your vehicle than LED bulbs do, so the resistor is necessary to equalize the energy load and prevent overly rapid flashing.

How do LED turn signal bulbs work?

When you want to upgrade your car’s turn signals from yellowed, dim Halogen bulbs to newer, brighter, better LED bulbs, you may notice that they are blinking much faster than your previous bulbs.

  • You may also notice that the lights do not come on at all or are very dim if they do not have a built-in resistor.
  • You’ll notice this pesky “hyper-flashing” occurs if you have not switched to an LED bulb with a built-in resistor.
    • Fortunately, this issue is usually an easy fix (one you can attempt yourself or make a trip to a professional to tackle the problem).
    • You can choose an LED bulb model that already features a resistor before making the switch in order to sidestep the need for correction altogether.
  • Luckily, Underground Lighting offers an array of LED turn signal bulb models featuring innovative technology that prevents hyper-flashing from occurring in the first place.

The purpose of resistors in LED turn signal bulbs

  • Hyper-flashing is, surprisingly, an intentional function activated by your vehicle’s turn signal circuit.
  • This turn signal circuit alerts you when a bulb has burned out, so you spend less time driving around without fully-functioning turn signal bulbs.
  • The purpose of resistors in LED turn signal bulbs is to eliminate that worrisome hyper-flashing and to ensure that your new, brighter bulbs work properly, easing your mind and getting you back on the road in no time.

Best LED Turn Signal Bulbs to Buy

Underground Lighting is the #1 resource for all of your car or truck lighting and accessory needs. Take a look at our top picks for the best LED turn signal bulbs to buy for your vehicle’s instant upgrade.

3157 Switchback W/ Built in Resistors Dual Color LED Turn Signal Light Bulbs White/Amber No Hyperflash

  • This 3157 switchback led bulbs model is a direct replacement bulb for front turn signals that features simple, hassle-free “plug and play” installation.
  • A built-in cooling fan extends the life span of the bulbs, only turning on when the high filament is engaged in order to reduce heat.
  • 1200 lumens per bulb
  • Nonpolar, CK-compatible electrical design assures no hyper-flashing or error codes to cause unnecessary worry.

7440/7443 Amber Turn Signal LED Bulbs

  • They feature 500 lumens per bulb, and a convenient plug and play installation process. No complicated wiring or slicing is necessary to make the simple switch.
  • Full metal heatsinking means reliable, long-lasting operation you can count on.
  • Four-sided illumination and a projector lens on top, coupled with increased light output and LED appearance means bright, unmistakable light in darkened driving conditions.

7443 Switchback W/ Built in Resistors Dual Color LED DRL Turn Signal Light Bulbs White/Amber No hyperflash

  • This 7443 Switchback bulb is a direct replacement bulb for turn signals and features CANBUS LED switchback that only has a built-in resistor on the turn signal filament.
  • This protects the LED from constant heat exposure, eliminating hyper-flashing or error codes from causing the driver needless stress.
  • A built-in cooling fan prevents overheating and extends the longevity of the bulbs.
  • Dual-colored, LED lights cover 360-degrees for maximum light output.
  • Of the 54 SMD LEDs in the impressive design, 18 are for white, and 36 are for amber.

If you’re not sure which of these top-rated LED turn signal bulbs to choose for your car or truck’s lighting look upgrade, don’t hesitate to reach out to a member of the Underground Lighting team. They’re ready and waiting to answer all of your questions and concerns with knowledgeable expertise.

What are you waiting for? Stop driving around with outdated, under-performing Halogen bulbs. Upgrade your ride with industry-leading auto lighting products and accessories from Underground Lighting. Getting started is easy! You can call, reach out through live chat, send an email to jump start your fresh new lighting look.