bartamos, going by your suggestion I came up with the following. The signal only operates two bulbs at a time. I checked the bulbs and they are rated at 21watts each. So 42/6=7amps, I guess that might explain why they are blowing the 6amp fuse. I'm surprised why this only occurs when the headlights are on even though they are on a different circuit. Coincidental I suppose. Will try a 10amp fuse and see what happens.
