Hyper Flash, Load Resistors and Indicator Compliance
Swap your indicators to LED and they'll often start flashing at double speed. That's hyper flash, and it puts your indicators outside what the Australian Design Rules require. Here's the electrical cause, the legal flash rate, the two fixes that actually work and what to check once you've fitted one. It's written for owners upgrading the indicators on a Toyota LandCruiser 70 Series and other vehicles, and for anyone who needs to get through a roadworthy inspection after an LED change.
What hyper flash is
Hyper flash is an indicator that flashes noticeably faster than normal after a globe change, typically at twice the usual rate or more. It shows up straight after you swap incandescent indicator globes for LED units. Your indicator still lights up. The fast flashing tells you the electrics are mismatched, and in most cases it's a compliance problem too.
Nothing is wrong with the LED globe. Your vehicle's flasher system is reacting to a change in electrical load exactly the way it was designed to, and once you understand that design you can fix the cause instead of masking it.
Why LED indicators cause hyper flash
An incandescent indicator globe draws a fair amount of current, commonly in the order of 1.5 to 2 amps each. Your factory flasher unit, or the body control module doing the flasher job in newer vehicles, watches the current flowing through the indicator circuit. That's how the vehicle knows a globe has blown.
When a globe fails, current draw on that side drops. The flasher sees the reduced load and doubles the flash rate on purpose so you notice. It's the standard bulb-out warning built into your vehicle, and it's a safety feature in its own right.
An LED draws far less current than the incandescent globe it replaces, often only a fraction of an amp. To the flasher, that low draw looks identical to a blown globe. So the system does its job and doubles the flash rate. You end up with hyper flash on every LED indicator while all the globes are working perfectly.
What ADR 13 requires for flash rate
ADR 13/00 (Installation of Lighting and Light-Signalling Devices) governs how lamps and indicators are fitted and how they must operate on a vehicle. Among its requirements, a direction indicator must flash at a steady rate of 60 to 120 flashes per minute. That's between one and two flashes per second, with a consistent on and off cycle.
Hyper flash pushes your indicator well above that range. Anything over 120 flashes per minute doesn't meet the requirement, and it makes the indicator installation non-compliant with the applicable ADRs for vehicle lighting. A flash rate outside the legal band is a defect that can fail a roadworthy inspection in any Australian state or territory.
There's a safety side to it as well. The band exists so a turn signal is unmistakable to other road users and can't be confused with a hazard, a brake lamp or a steady marker lamp. At three or four flashes per second your indicator reads as a fault or a hazard instead of a clear turn intention, and traffic behind and ahead of you loses that clarity. Getting the rate right keeps you understood on the road, not only signed off at inspection.
Problem, cause and fix
Nearly every symptom you'll have after an LED indicator upgrade traces back to the same current mismatch. Match your symptom to its cause and the remedy that goes with it.
| What you're seeing | Why it happens | What fixes it |
|---|---|---|
| Hyper flash (indicator flashes roughly twice the normal rate or faster) | LED draws far less current than the original globe, so the flasher reads it as a blown globe and doubles the flash rate | Fit a load resistor on the affected circuit to restore the original current draw, or fit a purpose-made anti-hyper-flash module or electronic flasher |
| Bulb-out warning on the dash or in the driver display | The body control module monitors indicator current and reports the low LED draw as a failed globe | Restore correct load with a resistor, or use an LED-compatible flasher or canbus-compatible module that doesn't rely on current to detect a globe |
| Flash too fast on one side only | Only one side was converted to LED, or one resistor is missing or not making contact, so the loads are unequal | Apply the same solution to both sides so the load is matched, and confirm every resistor or module connection is secure |
| Indicator works but flashes irregularly or intermittently | Loose connection, poor earth, or a resistor that is overheating and dropping out | Check and clean connections and earths, confirm the resistor is the correct value and is mounted to dissipate heat properly |
Load resistors
You wire a load resistor in parallel across your indicator globe or its wiring. It pulls extra current so the total load on the circuit matches what an incandescent globe would have drawn. With that load back, the flasher stops reading the circuit as a blown globe and your flash rate returns to normal.
Load resistors work and they're widely used. They're most often specified at 6 ohms and 50 watts for a circuit replacing a standard indicator globe, though the correct value depends on the original globe and your vehicle. The catch: the resistor turns the saved current into heat. A 50 watt resistor can get very hot in normal operation, and that changes where you can mount it.
Install a load resistor correctly
- Wire the resistor in parallel with the indicator, across the signal wire and earth for that lamp, never in series with the globe.
- Fit one resistor per indicator circuit you've converted to LED. Front and rear on the same side usually flash from the same circuit, so check how your vehicle is wired before you decide on a count.
- Mount it on clean bare metal that can act as a heat sink, away from wiring looms, plastic trim, fuel and brake lines, and anything else heat can damage.
- Keep it off painted or coated surfaces that can scorch, and clear of anywhere a hand could touch it during normal servicing.
- Use a connection method and crimps rated for the current involved, and make sure the earth is solid. A poor earth gives you the irregular flashing listed in the table.
Anti-hyper-flash modules and LED flashers
The second fix goes after the flasher instead of the load. A purpose-made anti-hyper-flash kit, an LED-compatible electronic flasher or a canbus-compatible module changes how the system decides the flash rate, so it no longer hangs on the low LED current.
You get a few things a resistor can't give you. There's no waste heat, your LED conversion keeps its reduced current draw, and a vehicle-matched module clears the dashboard bulb-out warning that resistors alone may not shift where the body control module does the monitoring. Which module you need depends on your vehicle and on whether the flasher function sits in a standalone flasher unit or in the body control module, so it has to be matched to the specific vehicle.
Either way the target is the same and ADR 13/00 sets it. Your indicators must flash at a steady 60 to 120 flashes per minute, with no false bulb-out warning, on both sides.
Confirm correct installation
Once your load resistor or module is in, check the result before you drive on it or present the vehicle for inspection.
- Operate the left indicator and confirm the flash rate looks normal and steady. Operate the right indicator and confirm it matches. Both sides should flash at the same rate.
- Confirm there's no bulb-out or globe-failure warning on the dash or in the driver display with the indicators operating.
- Operate the hazard lights and confirm all indicators flash together at a steady rate.
- Check the indicator self-cancels correctly after a turn where your vehicle has that function.
- With a resistor fitted, run the indicators for a period, then confirm the resistor and its surrounds aren't touching anything heat-sensitive and the flash rate stays steady once it's warm.
Still flashing fast: a connection is loose, the resistor value is wrong, or you've only done one side. If a bulb-out warning hangs around after you've fitted resistors, your vehicle most likely needs a module-based solution because the body control module is still monitoring the circuit.
Indicator upgrade products
PVS Automotive supplies the parts to convert your indicators to LED and keep the flash rate compliant. Everything you order is matched to your specific vehicle and plug and play.
- To make the conversion, fit LED indicator globes in place of your factory incandescent globes.
- For hyper flash and bulb-out warnings, add the indicator load resistor wiring kit, which restores the correct current draw so your indicators flash at the legal rate.
The LED indicators topic in our compliance resources covers choosing and fitting LED indicator globes and what to expect after the change. If your variant or build year isn't listed for a part, contact our team before you order and we'll confirm the right solution for your wiring.
Roadworthy and certification
An indicator flashing outside the 60 to 120 flashes per minute band is a defect that can fail a roadworthy inspection. So is an indicator that's the wrong colour, that doesn't work, or that throws a persistent fault. Fix hyper flash so your indicators flash at the correct steady rate and your lighting stays compliant with the applicable ADRs for vehicle lighting and with the state roadworthy requirements.
- NSW: indicator operation is checked at inspection. Certification under VSCCS may apply where lighting changes form part of a larger modification.
- VIC: lighting is assessed at roadworthy. VASS certification may apply where the change forms part of a modification affecting safety systems.
- QLD: indicator function is checked at inspection. Contact TMR, or an Approved Person under the scheme it administers, for guidance on your situation.
- SA, WA, TAS, NT, ACT: refer to the relevant state or territory scheme.
For how the Australian Design Rules work and how they meet state inspection, read What are Australian Design Rules? Full detail on each scheme sits in State and Territory Requirements. You can ask us for independent engineering assessment documentation to support certification and insurance disclosure in any state. Confirm requirements with a licensed automotive engineer and your insurer, and treat any change to your vehicle's lighting as something to disclose.
Last updated: June 2026