I have a 4 gauge wire running to my trunk to power my cute little 240 watt amp (baby amp I know) that powers my 6x9s. Now you may be wondering, big wire small amp? But subs are in the future so I figured I'd just do the big wire right away. I still have to drop an inline fuse in my car, what amp fuse should I get? Since I have the 4 gauge I have to get the glass fuses, if I would've gone with smaller wire since I could've used the blade fuses and just keep going up til they stop blowing but the glass I have to order one amp rating. What size do you think I should use, I was thinking 30 amps? I'm running probably 150 watts total between the speakers, any input is appreciated.

 

30 amp is fine,
im using a 4gauge also and my battery is in the trunk with a 1000 watt amp, im using a 80amp and its not a glass fuse

 

I was looking on crutchfield and for the 4 gauge they had the large inlines... for the smaller wires like for when I run some leds I'm just getting the small blade fuses since the wire going in to the fuse box is small.