Hyperflash & The Dash

Even today, LEDs might not be the default for that modern motorcycle purchase. If we splice additional lighting into an already existing circuit, one that will continue drawing the same amount of current, we're likely in the clear. A complete incandescent to LED swatch, however can trigger distracting nags on our dashboard. One example is turn signal hyperflash. Diodes, resistors and relays are the remedy.

Hyperflash beats Diode

A diode is basically the nightclub bouncer of our wiring harness. It only lets electricity through in one direction, telling it to get lost otherwise. On a motorcycle, that's a big deal when mixing and matching circuits. Running one brake light with multiple switches is one example. Keeping our signals from back-feeding into each other is another.

That said, a diode won't fix hyperflash. It's about one-way flow, not load simulation. Without a diode, that crisp left blinker moment might suddenly illuminate the right one too, turning clear communication into a Vegas floor show.

Aomorikuma, Wikimedia

Their operation is simple enough. Diodes are semiconductors that allow current to flow in a single direction (forward bias) and blockade the opposite (reverse bias). Think of it as a one-way valve for electricity. Wired in-line, the diode ensures that one switch doesn't accidentally power the wrong component. The beauty here is that it's passive: no moving parts, software or overthinking ... just a silent traffic cop keeping the juice where it belongs.

The math side of picking the correct diode ain't rocket surgery. Check the voltage rating first (must handle at least a bike's 12V system and preferably more for safety). Then check current handling. Make sure it can tolerate the amps those LEDs or bulbs are sipping without frying. Finally, mind the forward voltage drop (the little bit of juice the diode consumes just for existing).

For LEDs and small signals, this loss is usually negligible but pick a wimpy diode and it'll cook itself faster than a cheap clutch on a learner bike.

Resistor Beats Hyperflash

Resistors are the diet plans of the electrical world. Their entire purpose is to slow down how much electricity a circuit gobbles up. On our bike, this matters when we've swapped out big ol' incandescent bulbs for sippy-cup LEDs. The stock system expects a higher current draw so when it sees less, it panics and goes into hyperflash mode, blinking like we're signaling the end of days. A resistor convinces the bike everything is normal by burning off extra current as heat.

Inside every resistor, a material fights electricity's passage. That resistance slows the flow of electrons, converting the excess energy into warmth. For turn signal use, wire them in parallel with LEDs to simulate the same power draw as a factory bulb. This fools our bike's relay or ECU into thinking nothing has changed, even though we're rockin' low-draw lighting. Call it "cosplay for electrons".

In practice, a properly sized resistor supresses hyperflash without changing out switchgear.

Onto the calculator watch, where Ohm's Law (V = I x R) guides calculation. We need to figure out the difference in current draw between our old bulb and the new LED, then size a resistor to eat that difference without setting our wiring loom on fire. Wattage rating also matters as their aluminum bodies get hot enough to fry bacon. Pick too weak a resistor and it'll burn up, too strong and we're wasting battery life. Aim for balance and it'll cure hyperflash without adding gremlins.

Relays Are Better

If there's middle management in the electrical component world, it's the relay. It doesn't do much work itself but does tell bigger currents where to go using a smaller control signal. On motorcycles, relays are everywhere (starter, fuel pump, horn, you name it). In blinker world, an electronic flasher relay is our upgrade ticket when resistors seem like caveman tech. Swap the stock thermal flasher for a modern LED-friendly relay and suddenly those signals blink at the right tempo, no matter what bulbs we run (no more hyperflash).

Deconstructed, relays are just a switch that an electromagnet operates. When a small current flows through its control side, it creates a magnetic field that closes a heavier-duty switch on the power side. That allows a low-power handlebar switch or ECU output to safely control bigger loads without melting. For turn signals, the old-school thermal flasher used the heat of a bimetal strip to make that click-click cycle. Modern solid-state relays time it electronically (way more accurate, way less drama).

First, match the relay's voltage rating to the bike (12V, unless you're wiring a space shuttle). Then make sure its amp rating comfortably exceeds the current draw of whatever it's switching. If we swap to an LED-compatible flasher, ensure it can handle super low loads without throwing a tantrum. Some even allow flash rate adjustment with a little dial, perfect for tailoring blinkers to either "responsible commuter" or "disco strobe". Either way, it's a clean fix for hyperflash.

Conclusion

Hyperflash is just a bike's way of complaining when it doesn't see the current it expects. The good news is we've got options to shut it up. Diodes, resistors and relays each play their role but not every fix is created equal.

Resistors can do the job but waste energy as heat. Relays are often the cleaner, long-term solution when swapping to LEDs. Choosing the right path depends on comfort level and how tidy we want the wiring to be.

If you're ready to take the LED upgrade further, check back for our LED license plate turn signal installation guide. With the right setup, those signals stay sharp, reliable and free from hyperflash.

What Other Hyperflash Remedies Have You Employed?

There are plenty of auto-electronic fixes out there. Which ones have you put to use and why? Your input is invited. Leave a comment and/or write an article!