That is a very good question and no simple answer. Indicator relays for traditional halogen style bulb indicators rely on a certain amount of resistance being present in the indicator circuit to operate at the correct flash rate. LED indicators have a much lower resistance value, this leads in higher currents tripping the relay much quicker, hence the hyper flash scenario.
If you are replacing all four indicators with LED from bulb then usually the easiest way to resolve hyper flash is to use an LED specification indicator relay. Pick one with the same connections as the original, ie 3 pin for 3 pin…
However if only replacing one pair of indicators or the indicator relay is not changeable, (it can be part of the ECU or if more modern a can-bus system) this is when resistors can came in to play. These are connected in parallel with each indicator and mimic the resistance levels of a standard bulb. Resistors come in different values, you may need a different resistor when replacing a 10w bulb than when replacing a 21w bulb.
Some bikes such as the modern Bonneville have a setting under the dash menu to change indicators modes from bulb to LED so they are quite easy to swap over. For other can-bus systems we have a Can Bus Wizard box of tricks. This has a set of dip switches which can be cycled through to give a large range of resistance values. You simply run through the settings until an acceptable indicator flash rate is achieved. Each Can-Bus Wizard has two channels so can run two indicators ie front or rear.
If you need any more informatiuon please do not hesitate to ask.
Kind regards Simon Parker
