trusting that you are serious. you should immediately remove the "larger fuse" you installed. Heres why; an 8 amp fuse would be the weakest link in a circuit constructed of wire designed for up to 10 amps...if there is over current, the fuse sacrifices itself thru self-destruction and signals that something is wrong. It "protects" the circuit from the fault. But, if a human puts a larger fuse, like maybe a 16 amp fuse in the same circuit, guess what? You just made the WIRE the weakest link in the circuit. And when the overcurrent heats up the wire's insulation and it catches on fire and ignites the insulation in your car and the rug and the seats, don't say you weren't warned.

BTW, do you park this car in your garage at night?