Flasher Units
A flasher unit is the relay that makes a tractor's indicators and hazard lights flash at the legal rate of 60 to 120 flashes per minute. This range holds electronic and thermal flasher units in 12V and 24V with 2-pin, 3-pin and 4-pin connectors, load-independent units for LED indicators and heavy duty units for tractors towing a trailer.
Types of flasher unit in this range
Thermal flasher units are the original type, dependent on the lamp load, for two or four bulb indicators. Electronic flasher units flash at a constant rate regardless of load and give a warning when a bulb fails. LED flasher units and load-independent units keep the rate correct when indicators are changed to LED, which draw too little current for a thermal unit. Trailer flasher units are rated for tractor plus trailer, typically 2+2 or 4+2 bulbs, with a pilot lamp output.
Choosing a flasher unit
Match the voltage, the pin count on the old unit and the total number of indicator bulbs including the trailer. A tractor with LED indicators on the cab and bulb indicators on a trailer needs a load-independent unit to flash both at the same rate. Hyperflashing after fitting LED lamps is the sign of a thermal unit that needs replacing with an electronic one. Indicators and hazard lamps are under flasher lamps, and the hazard switch under switches.