Understanding Hyperflashing
Causes and Solutions for Headlights and Tail Lights
What is hyperflash?
Hyperflash is a term used to describe when the turn signals on a vehicle blink much faster than normal.
What causes hyperflash?
Hyperflash is caused when the vehicle’s turn signal relay detects a lower electrical resistance from the bulbs, which typically happens when a bulb goes bad or after installing LED turn signals. LED bulbs draw significantly less power compared to traditional halogen bulbs, so the vehicle's system mistakenly interprets this as a burned-out bulb, triggering a rapid blinking, or hyperflash, as a warning signal.
What can we do to resolve hyperflashing?
The solution to hyperflash depends on the specific lights or vehicle involved. Below are the most common the solutions (they will differ between lights/Vehicle):
What is a resistor & how does it help?
A resistor is an electrical component used to regulate the current flow and prevent issues like hyperflash. LED bulbs consume less power than traditional halogen bulbs, which can cause the vehicle’s system to mistakenly think a bulb is out. The resistor helps mimic the power draw of a halogen bulb, allowing the system to recognize the LED correctly and prevent hyperflash or error codes.
Lights that use a Halogen bulb with the turn signal:
For lights that use a halogen bulb in line with the LED turn signal, (which helps draw power to act as a resistor to prevent hyperflash) hyperflash can occur, for one of two reasons:
- LED Replacement: If the halogen turn signal bulb has been replaced with an LED bulb, hyperflash can occur because halogen bulbs act as resistors. To prevent this, the halogen bulb should remain in place.
- Bulb Failure: The halogen bulb may have burned out, which can trigger an error code. In this case, simply replacing the faulty bulb will fix the issue.
Full LED turn signal lights:
A full LED light is a light that no longer uses any bulbs for the turn signals. The following lights fall into that criteria.
Toyota: (For 3rd gen Tacoma TRD+ models the DRL harness is optional, but features will be missing)
Toyota vehicles may experience hyperflash for two main reasons:
- DRL Harness: All Toyota vehicles that fall under this category will require the DRL harness to be correctly installed for the turn signals to function properly.
- If aftermarket tail lights with LED turn signals are installed (such as Alpharex or another third party), we recommend installing 10-OHM resistors (SKU: AHL-LR-10OHM-2PC) on either the headlights or tail lights to prevent issues like hyperflash. If the vehicle is running only our headlights or only tail lights, please ensure everything is installed correctly and that any necessary adapters are in place. Once that is confirmed and the issue is still present, consider adding a resistor to address it. These resistors can be obtained by reaching out to our customer service team.
- Check all 3 fuses from the DRL harness to verify that they are seated properly and none have shorted out.
- Verify that the black (-) ground wire from the DRL harness is secure and relocate the DRL ground wire directly to the negative (-) terminal of the battery for a more secure connection.
Honda, Infiniti, Nissan & Subaru:
If the vehicle has aftermarket tail lights installed with LED turn signals (such as Alpharex or other third-party lights), we recommend installing 10-OHM resistors (SKU: AHL-LR-10OHM-2PC) on either the headlights or tail lights to prevent issues like hyperflash. If the vehicle is running only headlights or tail lights, please ensure everything is installed correctly and that any necessary adapters are in place. Once that is confirmed and the issue is still present, consider adding a resistor to address the issues. These resistors can be obtained by reaching out to our customer service team.
Domestic Vehicles (Dodge, Chevy, Ford, GMC, Jeep):
For domestic vehicles, it is common for issues with the BCM (Body Control Module) to be more frequent due to the CANBUS system. Most solutions for hyperflash are similar across these models.
- 12-Volt Reset: If hyperflash occurs, perform a 12-volt reset by disconnecting the negative battery terminal for 30 minutes to see if it resolves the issue.
- Resistance Check: If the issue persists, verify whether both LED tail lights and headlights are installed. If both are present, we can provide 10-OHM resistors to attach to the existing resistor on the back of the headlights or tail lights.
- Single Light Setup: If the vehicle has only LED headlights or tail lights (but not both), check for installation issues, ensuring all connections are secure. If hyperflash continues, start by adding a resistor. If that doesn’t resolve the issue, consider replacing the existing resistors.
Special cases:
GMC & Chevy:
- For specific models like the Tail lights for 2014-2018 Silverado, 2015-2019 Silverado HD, and 2014-2018 GMC Sierra 1500/HD, the existing resistor will need to be replaced rather than simply adding an additional one.
- For the 2016 – 2018 GMC Sierra if the customer is experiencing hyperflash please make sure that the customer does not need the converter as the light will plug in without it. If they have stock LED headlights they will need it.
Ford:
- For Super Duty vehicles, it is recommended to use an OBD reader to clear any error codes when hyperflash occurs, as in some cases, the issue will not resolve until the codes are cleared, and this could trickle to other models as well.
- For 2009-2014 F-150s, connect the turn signal bulb directly to the OEM turn signal plug to check for a signal. If none is detected, inspect the relays and clear any error codes, as the issue may be more vehicle-related.
- In some cases, a tuner like FORScan can be used to modify the vehicle’s settings from halogen to LED, allowing it to detect the lower voltage from LEDs.
Dodge:
Dodge vehicles vary in their response to LEDs, so the experience may differ for each owner. To resolve hyperflash across all generations, we recommend starting a 12 volt reset then with a 10-ohm resistor installation. Alternatively, a tuner such as AlfaOBD can modify the vehicle’s settings from halogen to LED, allowing it to recognize the lower voltage. For further assistance, contact our tech support team.