Why LED Load Resistors Are Needed ?

LED load resistors are needed to ensure that LED bulbs function correctly in circuits originally designed for incandescent bulbs, in automotive applications.
The primary reason is that LEDs draw significantly less current than traditional bulbs. This low current can confuse the vehicle’s onboard electrical system, which expects the higher current draw of incandescent bulbs, resulting in issues like hyper-flashing turn signals, dashboard bulb-out warnings, or LEDs not functioning properly.

LED load resistors are needed for several key reasons in automotive lighting applications, especially when upgrading to energy-efficient LED bulbs.​

Prevent Hyper-Flashing: When LED bulbs, which draw much less current than incandescent bulbs, are installed, vehicle flasher units often interpret the reduced load as a bulb failure. This triggers hyper-flashing (rapid blink rate of turn signals). Load resistors draw additional current, restoring the normal flash rate.​

Eliminate Dashboard Errors: Modern vehicles have onboard computers or CANbus systems that monitor light circuits and expect a specific current draw for each bulb. Low LED current can trigger “bulb out” or error warnings. A load resistor simulates the original bulb’s power consumption so that the system recognizes the LED bulb as a proper load.​

System Compatibility: Some cars may disable certain lighting or comfort features, such as cruise control, if they detect a “fault” in the system caused by LEDs. By correcting the electrical load with resistors, all features continue to function as intended.​

Protect LEDs from Surges: In some cases, load resistors can help absorb excess voltage spikes in the circuit, offering an added layer of protection for sensitive LED electronics.​

Load resistors are wired in parallel with the LED bulb. They safely absorb (and dissipate as heat) enough current to simulate the electrical load of an incandescent bulb. This tricks the circuit into functioning as if an original bulb is still present, thus avoiding compatibility problems.

– Current Balancing: The load resistor is installed in parallel with the LED bulb, adding enough resistance to the circuit to match the current draw expected from an incandescent bulb.
– Signal Correction: By increasing the total load, the vehicle’s flasher unit or module detects appropriate current and stops the hyper flashing warning.
– Mimics Original Bulb: The effect is comparable to restoring the circuit’s “weight” so the system believes a standard bulb is present, ensuring normal blink rates.

The resistor absorbs extra current and dissipates heat, so correct mounting is necessary. Common values for automotive turn signals are around 6 ohms and 25 watts. One resistor per LED bulb is typical for reliable results.

The Gambeks smart load resistor module is an advanced, non-heating solution designed for automotive turn signal LED upgrades. It uses electronic circuitry to simulate the current draw of incandescent bulbs without the heat generation typical of traditional load resistors. Take a look comparison between the standard led load resistor and our smart electronic dummy load module

– Electronic Simulation: It electronically mimics the load expected by the vehicle’s onboard computer, ensuring error-free operation without generating significant heat.
– Direct Replacement: The module replaces standard “dummy resistors” or load resistors, allowing easy and compatible LED upgrades in automotive lighting circuits          monitored by vehicle computers.
– Heat Management: Unlike passive LED load resistors that dissipate power as heat and require mounting on a radiator, the SLM module remains cool during operation,     reducing installation complexity and fire risk.
– Error Correction: It prevents common LED retrofit problems such as dashboard error messages and hyper flashing by accurately simulating the electrical load of original  bulbs.

Read more about the Gambeks SLM  smart load resistor module (detailed technical specifications)

The Gambeks smart load resistor module lineup includes several models designed to electronically simulate the load of incandescent bulbs in automotive LED turn signal circuits. Each module is non-heating and does not require a radiator for installation

The modules use an electronic solution to simulate load, avoiding heat generation and installation complexity.​

SLM221xx models suit standard vehicles; SLM421xx models fit multi-channel or commercial vehicles where more signals require load simulation.​

This lineup provides reliable, error-free LED upgrades for both 12V and 24V automotive electrical systems.

Gambeks Smart Load Resistor Module List

• Smart Led Load Resistor 2 way 21 W 12V
• Smart Led Load Resistor 2 way 21 W 24V
• Smart Led Load Resistor 4 way 21 W 12V
• Smart Led Load Resistor 4 way 21 W 24V