I have both a 2 prong and a 3 prong flasher I could use. I first thought it was a two prong as I only saw 2 wires with plugs on them. But as I crawled under to plug it in I found the third. They are all right next to each other. I just assumed they are all for the flashers.
I used the test light to find the hot wire & have it correct. The other two are anyone's guess.
I'm not going to mess with it for a while - I have brake lights when I need them at the moment & don't plan to drive for a while.
I just received my new intake gasket so that will be be my project for the weekend.