New blinkers wont work properly

My buddy gave a set of front blinkers he had that he never installed. So I put tuem on my bike. The blinkers he gave me only have 2 wires the old ones have 3. So I hooked them up anyway, its on a Harley sportster so when I turn the bike on the blinkers go on for Tue running lights but when I hit the blinker the tronto blinker works but its very dim. The back blinker just lights up but doesn't blink. Is there a way to fix this problem or I just can't use these blinkers cause of the wire situation. Thanks for any advice

Unless you absolutely have to have them, I would get rid of them, cleans the look of the bike up.

I am trying to figure out front blinkers on a 86 fxr for someone. They put different ones on with only 2 wires but it has 2 bulbs also. They tapped to an orange wire in the headlight. When you try the blinker it will flash 1 time then stay lit, if I tap off the grn wire from other side of flasher the back work fine but both front flash. This is all done using the housing as ground. Might try using blue wire which runs to breaker for the light system when I get back to it. They tapped into the brn and the violet for left an right ok so that is why I'm thinking the blue cause maybe that puts flasher back in play using bikes orignal lighting layout?? Or maybe find more user friendly front blinkers..

Been looking online and found the lights I have been trying to make work properly on the gentlemans fxr and low and behold they are listed as marker lights not blinkers.