what am i doing wrong with this?

I have very limited experience installing car audio equipment, so maybe one of you guys can pinch in your 3 pennies into this? I keep burning the inline fuse every time I connect the battery and I don't know what i am doing to cause that.
I drive a 2004 Toyota Sienna. I installed an Alpine Power Pack 445U. Also have some good Pioneer speakers. JVC head unit. All this I installed a year ago and works well.
Santa brought me last Christmas a powered sub that fits under a seat. It is a Sound Storm Laboratories 10 inch LOPRO10. It is a 600W RMS and 1200W peak (although I think it is exaggerated probably). It has a 25A fuse in it.
I ran a power wire (approx. 22ft) from a battery in the engine compartment via an existing firewall opening to the sub which is located under the seat in the back row. I grounded the sub with about 1.5 foot wire to the floor (made a new ground connection, sanded down paint). Ran RCA cables and remote lead to the head unit. Installed an AGU fuse holder 15 inch from the battery positive terminal. Put in the 30A fuse in it as per sub manufacturer's recommendation. The amp install kit is 4 gauge from KnuKonceptz. Once everything was connected I connected the power line to the positive of the battery - a flash in the fuse holder and the fuse is burnt!
I checked the cable at the firewall opening and the insulation is intact. The cables are connected to the appropriate ports on the sub.
I don't know what might cause the failure. Does anybody have any idea? What am I doing wrong?
Thanks up front for all you time.

in addition to what Mr. IAAI said, when you ran the power wire, make sure that when you put the panels back on, if they are the type that use screws to hold them down, make sure you did not screw through the power wire. it sounds dumb but it does happen.

I never had the radio on when reconnecting the battery, but I will try al of these again and will let you know later today. Af far as the brand this unit had very good reviews from users an Amazon and I al only looking to add a little bit of bass to music. Nothing booming or shuttering windows or even moving the trunk cover. I think it will do.

If the fuse is blowing as soon as you put the fuse it (with the ignition and radio off) then the problem is either a short in the power wire or a bad amp.

If you have an ohm meter you can unhook the power wire from the amp and measure resistance to ground. If the meter shows "open" then more then likely the amp is bad. If the meter shows a short track it down and fix it.

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Kevin Pierson

OK, I found the cause. I disconnected the power from the sub and the fuse did not blow. I started looking and found that the folded rear seat's hinge in my minivan pressed on the power cable too hard and cut through the cable's insulation a bit and caused the short. I taped it with electrical tape and now all is good. Thanks so much for your help!

For future readers and searchers reading this looking for help with their issues, instead of buying a large amount of fuses which can be costly, just put a normal (non LED) 12v test light in line in place of the fuse. When applying power the light should come on and go out quickly. If it stays on you have a short. Just make sure the amp (remote wire) is OFF while doing this testing. You will only be flowing enough current to light the 12v test light bulb so you can leave it in place while doing the testing. Remove the amp, if the light goes out you know the issue is in the amp, if the bulb stays on you know you have a knicked or pinched wire.

Glad the OP got his issue resolved.

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To master and control electricity is perfection. *evil laugh*