12V Amp power cable Aftermarket.

[spazman1990]

Hey guys. im having a issue. my bat is on the right side of the car. and i don't have along enough cable to run the 12v power cable over to the fuse box and to the back of the car. or i would of done that already. My issue is that sense i have a low amount of cable i wanted to run it the shortest way. i've seen people take out the battery and what not. but i don't see how i can run the wires.



However on the inside of the car. you can see a blower.


Located right next to


But i wanted to run it rly rly close to the positive side of the battery any help willl be amazing.haha

[cooljess76]

That cable is too thin to run power to an amp, if that's your plan. You need a heavier gauge cable. The cable pictured will get hot and probably melt. There's a punch-out hole in the firewall right behind the battery. Punch the hole out, run the cable through it(you should use a rubber grommet or something to seal the hole around the cable), then have the wire run through a safety kill switch mounted under the passenger side dash so you can quickly reach over and kill power in the event of an emergency. From there, have the wire run under the passenger side kick panel/carpet and under the rear seat to the cargo area. From there, you mount either an inline fuse or a fuse block which can be found at any car audio store. Then run power to your amp. Or you could just run an inline fuse right after the battery, then run the cable through the punch-out hole, under the carpet straight back under the rear seat and into the cargo area to the amp. I highly recommend a kill switch though, just make sure it's in an easy to reach spot that won't get wet and won't ground out against the chassis. This thread should help as far as routing goes:
http://www.318ti.org/forum/showthread.php?t=27419

[cooljess76]

Here's what an inline fuse holder looks like and this is the size wire you need:

[spazman1990]

haha. thank you very much for the fast fast reply haha. what i was trying to find was the knock out hole below the battery i have a nice Gage wire that came in a kit that my bro hooked up in his car. i just didn't realize there was a bunch hole there. i saw the heat shield but it didn't look like you could do anything hah. funny thing is i used to bump using speaker wire to my old sub and stuff. never had a problem just double it up lul . yeah my brother has the cap and fuzes and **** in his car. i just jacked his sub and the wire. and now i have a sub haha. have to rebuild his gay evo anyway.. so. XD thanks for the info

[hotmilk400]

you can also do what i do, and drill a hole in your firewall. just be careful how you do it, and where. then use a rubber protector to prevent the sharp hole from cutting your wire.

also,

i will just give you some info real quick for your help since the wire looks kind of small. (sorry if you are fine, but just making sure) also, this is good info for everyone else to pass along.

the best way to rate the wire without spending to much money is to simply look at the fuses on the amp. (if you have 2 amps, then add the values together).

16 AWG = 12 AMPS
14 AWG = 15 amps
12 AWG = 20 amps
10 awg = 30
8 awg = 40
6 awg = 54
4 awg = 72 amps
2 awg = 100 amps

these numbers are from the NEC code book, not something i made up.

if you rate your wire size correctly, there is ZERO reason to waste money on a CAP. Caps are for people that can not run a big enough wire, or they have professional systems that have subs/amps that require MORE power then the battery can give out at any time. the average person should not need a cap unless they do not install the system correctly or battery has problems/ to small.

YOU HAVE TO BUY and use the correct size wire, or you WILL start a fire! this is NOT a joke. using a small wire and forcing to much power though it will cause the wire to get very hot very fast, and will melt the plastic coating on the wire. if it melts, it will touch the metal in your car, and will short out. if it does that, the wire will glow bright red and start your carpet or whatever it touches on fire and do some VERY serious damage.

i was installing subs for a LONG time, and one customer used 16 AWG wire for a small amp and it did just that, started a huge fire and almost killed him (since the car fills up with smoke while driving).

i hope that helps. it is VERY serious that you look at the fuse rating on your amp and match it with the correct size wire (or bigger).

[cooljess76]

+1 to everything hotmilk400 said. You should absolutely run 4 gauge or bigger(lower number) from the battery. FYI, the picture of wires I posted earlier were just wires I ripped out of my M3 when I gutted it. If you look closely, the larger red and blue wires are 4 gauge. The thinner red wire is 10 gauge. You should really consider running either a fuse block(if you plan on adding multiple amps or components) or an inline fuse like the one I pictured earlier IN ADDITION to the fuses that plug into your amp. Just make sure to use a fuse with the correct value. I like to mount the fuse block or inline fuse in the back near the amp for two reasons. First, if you're running a fuse block, it shortens the length of cable needed if you're powering multiple components or amplifiers. And second, It's right there and visible next to everything else when you're troubleshooting your system. You won't need to pop the hood to check the fuse(s). I've seen people run inline fuses right after the battery in the engine compartment, but personally I think it looks kinda ghetto. And last but certainly not least, you should really consider a circuit breaker/kill switch. Most amatures don't use them because they think the fuses offer enough protection, but what happens when you smell smoke? Turning the system off at the headunit simply isn't enough. You want to kill power completely and immediately. Plus, if any part of the system shorts or grounds out, the circuit breaker will pop and kill power automatically. Of course, this should be used in addition to your inline fuse or fuse block and the standard fuses that plug into the amp. Here's what the circuit breaker/kill switch looks like:
http://cgi.ebay.com/Stinger-200-Amp-...item3f057c8876

You want to make sure you mount it somewhere that you can easily reach from the driver's seat(underneath the passenger's dash is a good place) and make sure it's not touching anything metal.

[spazman1990]

Well hey. got a question for you guys. why would the car die just by having a ground and a 12 wire to the amp? i don't get why it does that. i mean what would having a another fuse do? my friends don't have the same problem as i do. at least if i don't drive the car for one day. i think it dies. not rly sure. i been busy with other things.

[hotmilk400]

if you disconnect the 12 volt wire from your battery, does the car still die right away?

NO:
If the car can hold a charge for 1 week without driving it AND the 12 volt wire is disconnected, then your amp is probably not connected to your headunit and is on 24/7.

YES:
if your battery still dies, even when you disconnect the 12 volt wire from the battery, then your car is draining the battery somewhere else (light left on, short circuit, or battery is just dead and needs to be replaced, or your alternator is almost dead. )

[spazman1990]

hotmilk400- then your amp is probably not connected to your headunit and is on 24/7.


Well how can my amp not be hooked up the head unit? If you disconnect the two rca cables you get no boom boom. And the remote wire is hooked up other wise the amp wouldn't turn on. and yes before i hooked up the amp the battery didn't die. .

[hotmilk400]

The remote wire, if installed wrong, would keep your amp on 24/7. if you either hooked it up to a wire that is not switched, or you hooked it up to a wire that has 12 volts 24/7, or somewhere along the line it is making contact with the 12 volt power cable coming from your battery.

if you have a light that lights up when your amp turns on, you can test this. if your car is not running and the light on your amp is still on, then it is hooked up wrong. you can also test it with a multimeter. use the multimeter on the remote wire and the ground. if it multimeter shows a change higher then 2.0 volts without the car running, there is some kind of problem.

if your amp fully shuts off and no power goes to your amp when the car is turned off, then it could be a few other things, but they are much harder to test then the amp. if that is the case, it is unrelated to the amp. my car last about 1 month without driving it, and i have 3 amps in my car. amps only draw power when you car is running.

and what did you mean when you said ""i mean what would having another fuse do?"" you do have a fuse on your 12 volt power cable as soon as it leaves the battery right? that is the only fuse you need. if you do not have that first fuse as soon as that power cable comes off of your battery and goes to your AMP, you could be risking a HUGE fire, as stated above. if your power wire shorts on anywhere for any reason, your whole car will start on fire.

[spazman1990]

Yeah i do not have a kill switch.. I understand that to people on this forum it's a rly good good idea to have one. but i ran speaker wire double up. and it never got hot to even start melting the wires. but once i get money i will diffidently get the kill switch. yeah my amp has a light on it. and when i turn the key off. the amp powers down. ill take out my head unit and Triple check the wire that comes off of it. i'm 99.999999999% sure that it's on the right wire. i did get the adapter for the head unit but i had to run 4 cables for the front two speakers and back 2 speakers. i mod a ****ed the back speakers into place. and ran cable and tucked it away. but i don't understand why the Wiring harness won't allow the speakers to get the signal. it seemed easyer to run wires. but with the stereo turned all the way up. and the bass and trouble at a good lvl for hearing the music and what not. in the near future i was going to take off the doors and hook up the two tweeters. but i need to put capacitors or resisters on it to not allow base to go through.. ha and now i'm getting tired. ha

[hotmilk400]

you need a fuse/breaker as SOON as you pull power off the battery or you will start a fire! and you should not use speaker wire. speaker wire is typically only 16 AWG, and when you double it up, you are only at 14AWG. 14AWG is only 15amps. if you are running a REALLY small amp, it might be okay, but what is more important is that you need a fuse as soon as you pull anything off of the battery. for example, say you are working on your amp, and the power wire falls off and touches the ground wire. your entire car WILL START ON FIRE. it only takes about 2 seconds of a dead short to start a fire. a fuse will short out the system in less then 1 second. 60 AMP fuses are about $2.99 on ebay, so get on that ASAP. i think pep boys only wants $5.99 or $9.99.

since you are only running speaker wire, you should really get a fuse that is about 15 amps, but here is a link to a 30 amp fuse.

http://cgi.ebay.com/30-AMP-WATER-PRO...item5d2eea774a

you really do not need to pull out your headunit. the easiest way is to just test the wire that is on your amp. do you have a multimeter? or something to test it?

if the amps are fully turning off, then you have a different problem. probally a battery that just needs to be replaced because it can not hold a charge, but you might want to test it further before you just replace the battery.

[spazman1990]

Originally Posted by hotmilk400

you need a fuse/breaker as SOON as you pull power off the battery or you will start a fire! and you should not use speaker wire. speaker wire is typically only 16 AWG, and when you double it up, you are only at 14AWG. 14AWG is only 15amps. if you are running a REALLY small amp, it might be okay, but what is more important is that you need a fuse as soon as you pull anything off of the battery. for example, say you are working on your amp, and the power wire falls off and touches the ground wire. your entire car WILL START ON FIRE. it only takes about 2 seconds of a dead short to start a fire. a fuse will short out the system in less then 1 second. 60 AMP fuses are about $2.99 on ebay, so get on that ASAP. i think pep boys only wants $5.99 or $9.99.

since you are only running speaker wire, you should really get a fuse that is about 15 amps, but here is a link to a 30 amp fuse.

http://cgi.ebay.com/30-AMP-WATER-PRO...item5d2eea774a

you really do not need to pull out your headunit. the easiest way is to just test the wire that is on your amp. do you have a multimeter? or something to test it?

if the amps are fully turning off, then you have a different problem. probally a battery that just needs to be replaced because it can not hold a charge, but you might want to test it further before you just replace the battery.

Yeah i have tools and a muti meter. i work on cars. as crazy as that sounds.. well the thing is i am using a good size wire for the ground and for the positive i just don't get why it would want do this i had to have the remote wire on the wrong wire.. thats all i can think. well i said i used to do the hole speaker wire to the amp back in the day in my other bmw.haha. i don't do that now. i believe i have two fuses on my amp right now. but my car over at my brothers house. but i will diffidently get the kill switch. i think ones a 12 and ones a 2 or a 4. not sure i will look into it and send you a message later on today. i have to do my moms rack and pinion. and i haven't slept yet.haha people tell me all the time that they have problems understanding what i say. i'm sorry if you are having a problem with reading my text. i don't know proper grammar and well Eniglish rly haha



well thats the amp i have and http://i68.photobucket.com/albums/i1...n61/img022.jpg


and thats the fuses

http://i68.photobucket.com/albums/i1...n61/img024.jpg

Not my amp bty. just a picture of it.

[hotmilk400]

the amp does not draw that much power, so you might actually be okay with using speaker wire as a power source as long as they are 16AWG at 2 of them.. if it only has a 15 amp fuse on the side, then it is under 200 watts of real power coming out of it and rated okay.

either way, test the remote wire with the multimeter.

when the car is turned on (where the radio works) test the Remote wire and the ground wire with your multi-meter. it should read about 12 volts.

turn off the car and test it again. it should read under 1 volt (really it should read 0, but normally it never does) if it reads any higher then 1.0 volt, you have a problem with the remote wire.

if it reads under 1 volt, your battery dying has nothing to do with the amps (atleast from what i can tell you without being there)

also, the fuses on the side of the amp will not protect you if you do not have a fuse on that power wire as soon as it comes off of the battery. i stress to you that it is not something you should wait around for. you do not need an expensive kill switch or anything. just a cheap fuse/fuse holder for under $5. it should be located within 8 inchs from your battery. that is the only fuse you really need. the fuse on the amp only protects the amp not the wire running to the amp.

if you battery still dies and your amp is not a problem, then i am not sure what to tell you. it could be some short somewhere, or a battery going bad. at that point, i would search the website for a topic about it and follow the steps to test the car and see if it is just the battery (maybe bad cell) or something else.

best of luck

[cooljess76]

hotmilk400, I know you install car audio stuff as a profession, but my motto is do it right or don't do it at all. There's no way in hell I'd ever recommend using speaker wire to power an amplifier. It's a totally different type of wire for a totally different purpose. Power wire is designed for transporting electricity and speaker wire is designed for transporting signal. Not saying it can't be done, I'm just saying that speaker wire does not have the proper insulation to pass the high current that amplifiers demand and power cable does not have the proper shielding and precision winding that audio signals require. More importantly, there's a safety concern. As for the fuse being less than 8 inches from the battery, well in a perfect world, sure I'll give you that. But keep in mind the factory fuse box is a whole 4-5 feet away from the battery. All other e36's have the battery mounted in the trunk, so that's even further. Furthermore, the starter draws way more power than the amplifier and the fusable link located in the junction box above the cabin filter panel is more than 8 inches away from the battery. I'm just saying, having a bunch of aftermarket audio equipment in the engine compartment looks kinda ghetto IMO.

Here's how I think a system should be powered:

First, your connection at the battery should be clean and secure. You don't want a loose connection or frayed wires that can arc or short out on something. A simple crimp-on ring terminal is perfectly suffice, but if you want to get fancy, they sell multi-tap positive terminals:


Like I said before, you NEED to use a heavy duty power cable. Personally, I wouldn't use anything smaller than 4 gauge. Yeah, 10 gauge may be sufficient, but speaker wire is simply unacceptable. If you removed the punch-out plate that I mentioned earlier in the thread, you're going to need a BIG grommet. I tried to look up the BMW part number for the grommet used on e36's with trunk mounted batteries, however the grommet is only sold with the battery cable as an assembly. You may be able to find one that fits at your local auto parts store. The grommet MUST fit securely in the hole. If it comes out, the power cable can rub on the sharp edge of the firewall. Believe me when I say this is extremely dangerous. If the cable rubs on the metal firewall, it WILL eventually wear through the insulation and short out and IT WILL cause a fire. Your other alternative is to purchase a smaller grommet and then drill a hole through the firewall to the appropriate size of the grommet.


Once the cable is ran through the firewall, you should install a circuit breaker. In the event of a short or overload, the breaker will trip and kill power instantaneously. However, if your amp catches on fire, your sub blows or any other type malfunction occurs and you need to kill power immediately, you'll be able to reach down and do it with the quick press of a button. I recommend mounting it under the glove compartment. It makes no sense to put this in the engine compartment or anywhere that you cannot reach from the driver's seat in the event of an emergency. Race cars are required to have a battery cutoff switch INSIDE of the car for a reason.


From here, you'll want to route your power cable. If you took the time to read the writeup I linked earlier, you'll see that our cars a pre-fitted from the factory with a cable routing system for mounting the battery in the cargo area like other e36's. You can use this factory cable route to run your amplifier's power cable:
http://www.318ti.org/forum/showthread.php?t=27419

Now that your power cable is neatly ran back into the cargo area, you should install an inline fuse holder or a fuse block. I've seen amplifiers with melted circuit boards because the manufacturer installed fuses did not work or someone else installed a higher value fuse because it kept blowing the specified fuse. And if there happens to be a sudden spike in power or something grounds out, you'll want a fuse to pop BEFORE the amp. Yes, this is sorta what the circuit breaker is for, but it's better to be safe than sorry. Look at it this way, the circuit breaker protects your car, the inline fuse protects your amp. My reason for installing the fuse in the rear near the amp is not only to keep the engine compartment looking clean and uncluttered with tacky non-engine-related stuff, but it also allows you to quickly identify and replace a blown fuse when troubleshooting your system. If everything is tucked away nice and neatly in the rear, you won't find yourself running back and forth looking under the hood.


The key to having a nice system and making it last for many years is a CLEAN INSTALL. You don't want your amp sliding around on top of a rat nest of wires. IMO, a nice system should look as close to factory as possible. There shouldn't be any visible wires and FTM all wires should be cut to length, neatly routed and secured with zipties. Appropriate cable ends/connectors should be properly crimped or soldered and covered with heatshrink or supplied rubber insulators. Electrical tape is ghetto. Exposed wire is ghetto(and dangerous). Cutting corners, using improper materials and equipment is ghetto. But these are just my opinions. Take it for what it's worth, just trying to offer insight.

BTW, Everything I listed above could be purchased for under 50 bucks