Load resistors for LED turn signals: when and how
Load resistors solve the most common problem after replacing turn signals with LED bulbs - rapid flashing (hyper flash) and the burnt out bulb error on the dashboard. Here's why this happens and how to fix it.
Why are the turn signals flashing quickly?
The turn signal relay or the on-board computer monitors the consumption of the bulbs. A standard P21W bulb consumes 21 W, and an LED bulb - only 2-4 W. The system decides that the bulb is burned out and speeds up the flashing to warn the driver.
How load resistors work
The resistor is connected in parallel to the LED bulb and consumes the difference in power. Thus, the car "sees" normal consumption and the flashing becomes normal, and the error disappears. For turn signals, 50 W / 6 Ω resistors are usually used - one for each bulb.
Installation of load resistors
The resistor heats up during operation, so mount it on a metal surface, away from plastics and cables. Connect it with terminals or solder the connections and insulate them. If you are unsure, have an auto electrician install it.
Alternatives
- LED bulbs with CANbus - with built-in decoder, suitable for dimensions and number.
- Electronic turn signal relay - in older cars it replaces the standard relay.
Explore P21W LED bulbs и light bulb accessories.
Legal requirements
The turn signals must flash at a normal frequency and in the correct color (orange). The requirements for light signaling are described on the website of IAAA.
How to choose the right resistance
The resistor power must match the bulb you are replacing. For P21W and PY21W turn signals, 50 W / 6 Ω is used, and for W5W indicators - smaller resistors of about 5 W. Use one resistor per LED bulb, not one common one for both sides.
If in doubt, send us the make and model of your car and we will recommend an appropriate solution.
Frequently Asked Questions
Are they needed for the dimensions? Usually not - choose LED bulbs with CANbus. How hot does the resistance get? It can get very hot, so the installation location is important.
Conclusion
Load resistors are a small part that makes LED turn signals fully functional. Choose from the category load resistances - we deliver with Econt and BOX NOW.
