Stop taking short cuts!! Positive power should come off the ignition and Earth should go to the chassis at a spot of bare metal (screw,bolt whatever), not straight to the battery. Memory power should come off a constant source such as the cig lighter.
Then if it still blows at least you'll know it wasn't because you were being slack and there is some electrical fault.

__________________
No more GC8, sad face.
[SIGPIC][/SIGPIC]