flasher fuse blowing

Does it blow when you arm/disarm the alarm or when you use your lights.? Are we talking lights or indicators. If indicators you need to take the white lead from the 3.3, and join to your side light circuit if pos going. If neg, set it to neg. If you're using indicators take the white lead  (set the alarm for neg) and join to 85 on a relay, join 30 and 86 to a constant 12volts,fused 20 amps take 87 as the output and split via 2 x 1N5404 diodes, band out towards each indicator wire. I've done dozens of late 90s Imprezzas with never a problem.