need help with subwoofer + amplifier installation

[shiezan]

I've had a sub + amp system installed into my a4 for a while but the amp and speaker blew out. My technician disconnected the system because I told him I wanted to use the stock sound system until I save up for a new system. I think he mentioned to me that he was going to take off one of the fuses so the electric from my car wouldn't go to any external subwoofer system.
However, he left everything else as is, like the thick wire from the battery, the ground from the amplifier etc. I wired everything up for my new amp but when I turn on the car on it does not receive any power. I'm guessing it is because one of the fuses is still disconnected. I don't know which fuse to reinstall and which type of fuse I have to buy for it. Anybody know what I should do?

[Vinchenzo51]

Fuse should be in line somewhere right after the battery, something like this



You'll need a fuse like this one, probably 20a-30a

[daveman]

Use a voltmeter across the power terminals at the sub amp, should be ~12.5V with engine off and ~14.5V with engine on. Check continuity from ground terminal of amp to any exposed part of the chassis. Most likely the fuse though if the shop said they removed it. It may not look like the one above thogh, more likely an ANL or mini-ANL style one (flat with one with spades at either end facing 90 degrees to each other) but will most likely be in a similar looking fuse holder. The fuse holder should be in the engine bay close to the battery. If you find it and it's not within a foot or so of the battery positive terminal, install a fuse holder there. The fuse is to protect your battery/car electrical system more than to protect your amp. If anything cuts or wears down the outer sleeve of that power cable running to (I assume) your trunk shorting it to the chassis, the fuse will blow. If the short occurs at a point closer to the battery than the fuse, blowing the fuse will not stop you shorting your battery.

[$nooze]

Could also be the remote line from the deck that's disconnected.

[daveman]

Could also be the remote line from the deck that's disconnected.

yeah good call. measure with a voltmeter or put a small jumper between the amps +ve terminal and the remote in terminal to see if it comes on

[shiezan]

i ended up taking it to a shop where they installed the fuse for me. it turned out the high low converter was also burned out so they swapped that out. but after everything, the amp that i bought, nakamichi pa-1500 was defective. the power light would turn on when i turn on the car but there would be no output. we tried testing the set up with a different amp and the sound came out fine. so i guess i gotta exchange my amp with one that works. i guess subwoofer amps are really delicate and a pain to deal with.