I think Rob Valdez can help you out with a wiring schematic for the hazard flasher circuit .
Rob also made a posting back about 3-4 months ago, about a hazard flasher installation, that didn't require the additional wiring relay and switch .
There also is a diode in the wiring for the hazard flasher kit, I wonder if by chance the diode failed 'open' ?
The diode I'm talking about should be under the tank, it has a plastic guard around it maybe 4 cm or so long and 1 cm wide, with two push on type terminals, possibly wrapped in black cloth tape .
If the diode has failed, you can open it up, and replace the diode with a common type from an electronics store, I think a 1N4001, is a common diode readily available for low cost .