Running a higher rated audio fuse

[BananaBandolero]

I'd like to install an amplifier in my S14, not a particularly powerful one (4x45A), and it specifies the fuse for the audio system should be at least 15A. According to the FSM, the '97 S14 has 10A fuses to the audio system. Curious what you think about the options, or if I'm missing any...
- Just run the 10A fuse and expect that to be alright unless im playing white noise at max volume
- Put a 15A fuse in, assuming the 10A was a conservative choice. Search tells me large upgrades (like 10A to 30A) are asking for fires, but no one asks about smaller upgrades, so perhaps it's within the margin of safety
- upgrade speaker wiring (assuming that's the weak point?) or fuse box-->head unit wiring (maybe that's more likely the weak point) and then go with a 15A fuse
- bypass the fuse box and run 15A fused power to the audio system from the battery.

[ultimateirving]

so are you replacing the head unit? Because those have similar power (max watts around 4x50w) or is this a separate amp? If it's a separate amp it should have a dedicated power wire to the battery, and a 12v ign on remote wire.

[BananaBandolero]

I am also replacing the head unit, yes. Alpine (4x50W peak, 4x18W RMS) head unit to replace a lower powered Panasonic one. I also want to add Alpine's small 4x45W RMS amp to the system.

Plan is all here: http://imgur.com/Lbp2LLg

And I'm trying to figure out how to deal with that 15A requirement vs 10A stock fuse. Seems kind of small for running a whole new battery line.

[lunchmeat]

No need to worry about it. For the amp, run the 12v+ to the battery, with an inline 15A fuse. Remote wire goes to the head unit or a switched 12v source.
That's it.

[derass]

Using a larger fuse is asking for a fire. The gauge of the existing power wire was chosen for a specified current (10A), above that it can melt or catch fire. So the "weak point" is the wiring between the fusebox and head-unit. I think the idea of replacing that wire with the appropriate gauge is the best option retaining OEM fit and safety.

You can use a table like this for reference (this is just the first one I found on Google, you can do further research on your own).

https://s-media-cache-ak0.pinimg.com/736x/57/22/80/57228076ef240ed796b328a7d6387eac.jpg

[BananaBandolero]

Thanks fellas. Will go for the battery line.

[BananaBandolero]

I've been scoping out tapping direct battery power for the amp, but a decent wrinkle is that the battery has been relocated to the trunk, so a big 0-gauge wire runs up to the engine bay fuse box and then gets distributed from there. The amp is a small one that will live behind the dash... it actually fits as a pass-through between the stereo wiring harness and the head unit.

Rather than running a second wire to the trunk, taking a bunch of bodywork off in the process, can I tap the battery line where it comes into the fuse box somehow? I was considering...
- Tapping into the main battery wire shortly before it reaches the fuse box (maybe a terminal that splits it, or there's some kind of screw-into-the-wire tap?)
- opening up the fuse box and cutting/soldering into a wire there, probably the first one coming off of the 100A fuse

In either case I'd add an inline fuse. Hopefully neither of those is a terrible idea.

[Tyler_240]

I would suggest picking up a simple amp wiring kit from walmart. Just a quick search, but for $14.00 you can get something like this http://www.walmart.com/ip/Audiopipe-BGE4BB-Amplifier-Wiring-Kit-4ga-bullzaudio-blue-gold-Edition-Box/49455991

I would not mess with your main harness power. Don't be lazy. Removing the panels is not difficult, invest the time so you don't create electrical gremlins which could be a nightmare to track down later on.

You could quickly run the Power + Ground under the rear seats and under the center console, or alternatively, along the passenger side frame rail and up behind the glove box.

Put a 30A in-line fuse close to the battery (+) and use the 12v IGN wire from your head unit as your switched source.

[anti tyler]

Considering the stock audio fuse protects the stock radio; aftermarket radios have typically a 15A fuse imbedded in the rear of the unit, that protects the unit itself, which is ran off the stock 12+ radio harness.

The subs and amplifier are generally ran on a separate power source tapped and fused off of the battery itself, then a blue remote wire triggers the amp/subs into a power on state.


So as stated before, don't up your stock fuse location. The fuse that is in-line with amp/subs will protect that circuit. Your amp/subs won't be sending 15 amps into your head unit.


You probably don't want to tap into that wire, at least not how I picture it. Instead, you may want to hop on eBay and get a 1-TO-2 heavy gauge tap, where you chop the wire, screw it into the tap, and from there you connect the other side, then have your 4-8 gauge amp cable that taps into the other side as well. I've found A/C repair places carry similar taps and connectors for gauges that high. (At least in Jacksonville)