[jmeckel]

Make sure you have a 6 volt flasher, 6 and 12 volt look the same, they should have the operating voltage stamped on the case. The "normal" meaning non-solid state, flashers need current flow through them to operate properly. If you are using LED or low current lamps it will affect your flash rate, low voltage will also cause the same issue. Current is a factor of Voltage / Resistance. So if your battery voltage is low or the resistance of the filament in the light bulb is high ( lower resistance in a filament typically results in more light output), the current flow will be lower causing the flash rate will be slow or not at all.