after looking at the wiring diagrams you either have an open on the ground side in the front, or your power wires coming the front turn signals are shorted together, thats the only 2 things that would cause all 4 to flash at the same time. to narrow it down i would check to see if 3 of the lights are not as bright as the other one when using the turn signals, if theres an open in the ground wire, the power should be trying to find the ground through the other bulbs causing it them if all the bulbs are about the same brightness i would say that its most likely that you some how shorted the Ch and DG wires going into the front turn signals