Read the PM I just sent you(Discgogulfdude). Those units are meant to also work with 6 volt systems so I would imagine (without having proper data) the directionals use series resistors to create a voltage drop. To be safe I would say use the two resistors per side for the 12 volt system. If these are series resistors one set might be used 6 volt application so try the two resistors for the larger voltage drop from 12 volts. Now let's talk about the load resistors. The load resistors are wired in parallel, across the circuit to emulate the load for an incandescent lamp. This helps normalize flash rate but I would just replace the flasher relay with an electronic unit that flashes the same rate regardless of the load.
Please be aware that I'm working off limited data

and can only assume this is how these are set up. Try to confirm this is how these should be wired to be sure, so you don't toast them.:thumbup: