Use a multimeter on the wires to the indicator relay, there's two wires, turn a blinker on see what the reading is, if there's no power going to the relay the problem can lie with the ignition switch. I had the same problem and found the bolts that hold the ignition switch together (where you put the key in ) had come loose and although everything else worked fine the blinkers didn't. I tightened the bolts inside the switch housing and it sorted it. Could be the relay though , but if your indicators work with the alarm then could be that. I stripped the alarm off mine years ago it was a pita !