i would think that you have a bad earth that is causing a short on your indicator,i would take the light cluster out. take the oposite side out by undoing the screws either under the bonnet if front or in the boot if rear undo the elec plugs then plug the opposite side in to the side that you have the fault in etc it will tell you if the light unit has a fault or the wire fault eg a bad earth causing a short
george nixon
September 2009