need help: new turn signals installed and they don't work.

[thehooligan]

hey guys im not the best at electrical so this may be a dumb question:

i recently picked up two pairs of these: http://www.bikebandit.com/bikemaster-arrow-head-l-e-d-turn-signals

i installed the first pair on the front and tested them, they worked fine. when i installed the rear pair (so all four were on) none of them worked. any ideas? i was thinking a voltage problem or something but like i said i'm not good with the electrical system.

[skunkteeth]

This documents what you gotta do

http://gstwins.com/gsboard/index.php?topic=60138.0