I am using this on a 1973 Range Rover which has a two wire flasher unit. The conversion was very easy with the help of a multi-meter. The ignition controlled power (green/yellow) goes to the + terminal on the unit, the flasher switch (light green) goes to the L terminal. An earth must be provided for the - terminal. You may find that you have to use a second flasher unit to make the hazards work but the wiring would be similar. As this unit does not rely on load to control the rate of flash it can be used with either bulbs or led or combinations of the two. I hope this helps to take the mystery out of the conversion.