Up date-------- I have been told that there is a resistance device used on motorcycles for this purpose. It seems that the bulbs and short wiring harness on a motorcycle dont produce enough resistance to make the flasher flash. So you dont have to wire in bulbs to make it work, just go to a motorcycle shop and get the resistor box.
Once again try hooking it up with all the lights on the front working to see it will go ahead and work with out adding resistance.

I didn't do it, no one saw me do it, you can't prove anything! "Bart Simpson"