If you have one light working idt the relay would be the problem. Are you reading 12 volts at the ground because im pretty sure if you had power going to the light it should have 0 volts

 

Your problem can't be the relay if one light works like it's supposed to. You've got a wiring issue you did when you wired it up OR power is shorted to ground INSIDE the light that's not working.

Cut the pigtail where you crimped it and test the light to a power source, if it works you hosed up your wiring, if it don't, the light was phucked out the box...

 

Some other issues arose and put the light issue on hold, but I got them working - the problem was the ground of the one light. Once the test light came I was able to figure it out and the lights now work. Thanks for the help guys!