why do my vauxhall astra (1990) indicators keep blowing the fuses?

Blowing a 30 amp fuse is quite a serious problem, try removing the bulbs and using the correct fuse try again if the fuse is ok then something on one of the fittings is faulty shorting to earth when a bulb is inserted if the fuse blows, find the relay that controls the indicators remove it, replace bulbs and fuse and try again if it does not blow it is more than likely the relay if it does than it is either the switch mechanism or faulty wiring between the switch and the relay

David
May 2005