After upgrading your motorcycle to LED turn signals, you might notice that they blink too fast or even stay solid — a problem known as hyperflashing. The good news? There’s an easy fix: installing load resistors.
This guide explains exactly how to install resistors for LED turn signals on a motorcycle, why they’re needed, what tools to use, and how to wire them correctly — so your LED lights work perfectly and safely.
💡 Quick Answer: What Do Resistors Do on LED Turn Signals?
Resistors simulate the electrical load of your motorcycle’s stock incandescent bulbs. Because LED lights use much less power, your flasher relay “thinks” a bulb is burnt out — causing hyperflashing or malfunctioning indicators. Adding resistors restores the expected load, normalizing the blink rate.
Each resistor is wired in parallel with the LED turn signal — one resistor per side (left and right).
🧭 Why You Might Need Resistors
- ✅ You replaced stock bulbs with LED turn signals
- ✅ Your blinkers flash rapidly or inconsistently
- ✅ You have a CAN bus system that detects “low load” errors
- ✅ You don’t want to replace your flasher relay
Some motorcycles — like Harley-Davidson and Indian models — may require either load equalizers (resistors) or a dedicated LED flasher relay depending on the electrical system. Eagle Lights turn signal kits include plug-and-play resistors or built-in load equalization for easy installation.
⚙️ Step 1: Gather Your Tools and Materials
You’ll need just a few basic items to install resistors:
- Two LED load resistors (one for each turn signal circuit)
- Wire strippers or cutters
- Crimp connectors or soldering tools
- Electrical tape or heat shrink tubing
- Zip ties for wire management
- Multimeter (optional, to verify wiring)
Pro Tip: Purchase resistors rated for 6–8 ohms, 25 watts — the standard range for most motorcycle LED conversions.
📍 Step 2: Identify the Turn Signal Wires
Locate the wiring for your motorcycle’s turn signals — typically found under the seat, behind side panels, or in the headlight housing.
- Each turn signal usually has two wires:
- Positive (+): The power wire that activates the signal
- Negative (–): The ground wire
Use a multimeter or your service manual to confirm which wire is which — color codes vary by manufacturer (for example, black may be ground on one bike but power on another).
🛠️ Step 3: Decide Where to Mount the Resistors
Resistors generate heat when operating, so placement is important. Mount them in a secure, ventilated location away from plastic or painted surfaces.
- Ideal mounting spots include:
- On a metal frame rail
- Under the seat (attached to a bracket or heat-safe area)
- Behind side panels with metal backing
- Avoid wrapping resistors in tape or foam — this traps heat and can cause failure.
Some Eagle Lights LED turn signal kits include aluminum-cased resistors with pre-installed mounting holes for simple, heat-safe installation.
⚡ Step 4: Disconnect the Battery
Before you start cutting or splicing wires, disconnect your motorcycle’s battery — especially the negative terminal — to avoid short circuits or electrical shock.
🔌 Step 5: Wire the Resistor in Parallel
Here’s the most important part — wiring each resistor properly.
Each resistor should connect across the two wires of your LED turn signal (positive to positive, negative to negative). This creates a parallel circuit that simulates the correct load.
Basic Wiring Diagram:
[Motorcycle Wiring Harness]——(+)——[LED Turn Signal]——(–)
| |
[Resistor] <– connects in parallel
Steps:
- Locate the positive and negative wires of your LED turn signal.
- Strip about 1/2 inch of insulation from each wire.
- Connect one resistor lead to the positive wire and the other to the negative wire.
- Use crimp connectors, solder joints, or plug adapters to secure connections.
- Insulate the connections with heat shrink or electrical tape.
Note: One resistor is required per turn signal circuit (left and right). If you have four signals, install one resistor per side — not per bulb.
💡 Step 6: Reconnect the Battery and Test the Turn Signals
After both resistors are installed:
- Reconnect the negative terminal of your battery.
- Turn on the ignition (no need to start the engine).
- Activate each turn signal and observe the blink rate.
If everything is wired correctly, the lights should blink at a steady, normal pace — around 60–90 flashes per minute.
If you still experience hyperflashing or no flashing at all, see the troubleshooting section below.
🧠 Step 7: Troubleshooting Common Issues
| Problem | Possible Cause | Solution |
|---|---|---|
| LEDs still hyperflash | Loose resistor connection or wrong resistance value | Check wiring and ensure resistors are 6–8 ohms, 25W |
| Signals don’t blink at all | Reversed polarity or blown fuse | Swap resistor leads or replace fuse |
| Resistors get too hot | Mounted in insulated area or overused | Reinstall on metal surface with ventilation |
| One side blinks faster | Uneven load between sides | Ensure each side has one resistor installed |
Still having trouble? Consider replacing your relay with an LED flasher relay — it achieves the same result with less wiring and no heat output.
🌧️ Step 8: Weatherproof and Secure Everything
Once your turn signals are flashing properly:
- Seal exposed wires with heat shrink tubing or waterproof electrical tape.
- Secure resistors to the frame using bolts or zip ties — away from plastic and paint.
- Bundle and organize wiring with zip ties to prevent rattling or wear.
For year-round riding, durable wiring protection ensures longevity and reliability.
🔧 Step 9: Optional — Use Plug-and-Play Adapters
If you prefer not to cut or splice wires, many modern LED kits include plug-and-play adapters that connect directly to your stock harness. This simplifies installation, eliminates soldering, and makes future upgrades easier.
Eagle Lights LED turn signal kits are designed for easy plug-and-play compatibility, so you can avoid resistor installation altogether on most models.
💬 Frequently Asked Questions (People Also Ask)
Do I need resistors for LED turn signals?
Yes, if your turn signals blink too fast or don’t flash at all after switching to LEDs. Resistors restore normal blink rates by adding electrical load.
Can I use one resistor for all four turn signals?
No. You need one resistor per circuit — one for the left side and one for the right side.
Do resistors get hot?
Yes. Load resistors can reach temperatures up to 200°F, so always mount them on metal, not plastic.
What’s the difference between a resistor and an LED flasher relay?
Both fix hyperflash. Resistors simulate old bulb loads, while LED relays electronically regulate flash rate. Relays are cooler and easier to install, but not compatible with all motorcycles.
How long does it take to install resistors?
Typically 30–45 minutes for both sides, depending on your bike’s wiring access.
Will resistors drain my battery?
No, not when installed correctly. They only draw power when the turn signals are active.
🏁 Final Thoughts: Fix Hyperflash the Right Way
Installing resistors for LED turn signals is a simple and effective way to eliminate hyperflashing, restore proper function, and keep your motorcycle road-legal. With basic tools and a little patience, you can complete this upgrade in under an hour.
For the easiest solution, choose Eagle Lights LED turn signal kits — engineered with built-in resistors or plug-and-play compatibility for Harley-Davidson, Indian, and other major motorcycle brands.
Ride safe. Ride visible. Ride bright.
