So, bro solved ur problem already. For kancil check around..Some spare parts shop do carry higher capacity alternator.The cost less then rm200.I know because i bought one for my kancil and i upgraded the battery to bigger battery.Now i dont face any power shortage to the amp.Im enjoying the bass until even the rear view mirror vibrating.

Before you do that..Do your grounding.Ofthen grounding is the problem for older cars. Dont buy those cheap grounding cables.If budget is the problem..You can get from 1/2cut shop..those grounding cables fixed to evos,gtr etc at very cheap price of less than rm100.