ground sided switching require always on?

Alright gang, I've got a set of headlight flashers on my personal vehicle for when I must make runs to the PD stepped up. Here's the deal, being that my car (Mazda Protege) uses ground side switching, the wigwags (Galls brand) require that my headlights be ON before the headlights will flash. On our Crown Vics, which are positive switched, you do not need the headlights on first to flash them. If anyone's familiar with wigwags, is there a way to "trick" or otherwise allow my headlights to flash without being on in the first place? If it helps, the wiring is as follows: White: 1a fused constant Green: Ground to chassis. Red: Switched power. Yellow: To driver's side headlight, bulb side. Blue: To driver's side headlight, harness side. The car is down due to an electrical problem so I cannot test any wires but if someone has a ground side switched car and can help, PLEASE do. There must be someway to fire the main headlight's negative switch ONLY when the flasher requests a flash. Or so I'd think...

No ideas via relays? If I understood them a bit more, I'd have a go at it but alas, I don't..

Well the galls brand is one of the lower end. by the time you figure out how to trick the system you can find one that is meant for your  application. soundoff and able 2 if you go to there website you can get the right one for your car. i am running a code 3 711 flasher and it works fine on my f150, but i am positive side switching. the reason galls makes it to be on is yours is ground side switched so it is not able to work the way your car is set up , they are a universal type, if you need anymore help PM me and i can help ou out