kirksaeter88

I was wondering if there was any benefit to using a fused Distribution block instead of a non fused. I just got a smal 4 channel amp for my speakers and was wondering. Or would it be safer to run a second power line from the battery? Thanks

lurch519

do not use a fused distro block. put a fuse on a separate power wire from your battery within 18 inches

belkjz

if you are only using one amp you dont need a distribution block. i would use a circuit bkr under the hood, much more conveinant. if you were talking about tapping of another power source and using a distribution block i would probably just run the wire from the battery. all the wires in the car are too small for anything but the smallest amp (like one in a head unit). even if you just run ten gauge that be better then other car wires.

18bsTiRX8

When I installed systems in the past for our local stereo shop, we always fused 18 inches off the battery to protect the main power cable, then used a fused distribution block for the multiple power cables to the amps. The reason for the fused distribution block is because the main fuse block off the battery would be a much higher rated fuse (ie 80/100amp) for that main power cable....the fuse block would have smaller rated fuses to protect the individual power supplies to each amp. If you did not have this, and you developed a short in just one of the amps, it may or may not trip the large fuse in time to prevent a fire.

The non-fused distribution blocks reflect the same setup as above, just for the ground connections.

For example (a 2 amp system), fuse the 4 gauge power wire with a fuse block 18" off the battery....then use a fused distribution block dropping to, say, two 8 gauge power supply wires to the two amps. The ground side should be two 8 gauge ground wires to an unfused distribution block, which is connected to a 4 gauge wire to ground connection point.

jstkilntim

All of the above examples are correct in their own way. Here is a little more clarification. If you only have 1 amp and only plan to have 1 amp in the future, you can run the amp manufacturer's recommended size power wire directly from the battery with the amp manufacturer's recommended size fuse (or circuit breaker) as close to the battery as possible. Sometimes (especially on lower rated fuses) this fuse may blow due to the distance of the power wire, and you will have to install a higher rated fuse at the battery and the correct size fuse at the equipment.

If you have multiple amps (or other equipment) or are planning to add equipment later, you would need to run large enough power cable to support all equipment to a fused distribution block (or similar) with an individual manufacturer's recommended size fuse or circuit breaker for each piece of equipment. This is easier and more feasible than running individual power wires for each component. I prefer fuses over circuit breakers due to the cost. If installed properly, you will probably never blow a fuse anyway.

Remember, the fuse at the battery is for protecting your car, the fuse at the equipment is for protecting the equipment. Some equipment is internally fused and does not require external fuses, but you will always need the fuse at the battery. Never put a fuse with a rating that excedes the wires current rating. And always follow the manufacturer's recommendations.

kirksaeter88

Thanks alot, veryy good info. im adding a small 4 channel with a 30 amp rating and I already have a bigger amp w/ a 80 amp rating. the 4 channel is internally fused so I think Ill be fine with a regualr block instead of a fused.

18bsTiRX8

You should be okay, but its nice to have the extra protection of a fused block (they are about the same price too I believe...at least within $10 or so).

Since you already have an amp in place, be sure you replace the power wire before the distribution block to a size that can handle BOTH amps....ie if you are running 8gauge now, replace it with 4gauge to support both amps, and run the 8 gauge from the distribution block to the individual amps.

If you don't, you will either be blowing fuses at the battery, or the wire will get hot and melt (not pretty at all).

jstkilntim

Check this link to clear any confusion. http://www.the12volt.com/wiring/recwirsz.asp
It doesn't matter how many amps you have, it matters how much current they draw. In this case (I am guessing that you are running around the 700 watt range) the 4 gauge should be fine.

kirksaeter88

Thanks alot. This site is very useful. Would it hurt anything If I grounded both of the amps at the same point on the car?

jstkilntim

Nope.

kirksaeter88

Ive been searching but I cant find a good thread for running speaker wire into the front doors. Does anybody know a good DIY for this ? thanks

Asmoran

You have to drill new holes to do that. I just tapped into the stock wiring at the HU and used the pre-existing runs to get into the doors.

The problem is that the wire bundle in the doors goes through the long rubber grommet thing into a plastic connector, and there's no way around it.

Also, another thing about fuses and distro blocks. Most of the time, a distro block takes a large diameter power cable from the battery and splits it into 2 or more smaller cables to the amps. You need to add an appropriately-sized fuse to the large cable within 18" of the battery, the closer the better. This will protect your car in case something happens and the larger cable gets grounded. You also need to have a fuse on each of the smaller wires for the same reason. The smaller wires can't carry the same amount of current as the larger one, and it's possible to melt and burn one of the smaller wires before the fuse on the big wire blows. This can be a fire hazard if something happens (like an accident happens, and a metal panel slices into one of the smaller wires). You can either fuse the smaller wires (within 18" of the distro block just like the big wire and the battery), or buy a fused distro block. That's why they make the fused type.

forbidden

With some work it is easy to run new wires into the doors. Take your time and remove the boot and molex from the door jamb. Look closely at the molex for unused holes. Drill these holes out to run your new wire through. If you have to, split the speaker wire into two separate wires to make it easier to pass it through the molex.

kirksaeter88

[QUOTE]You can either fuse the smaller wires (within 18" of the distro block just like the big wire and the battery), or buy a fused distro block. That's why they make the fused type.

What If the amp is internally fused? do i still need an inline fuse on the small wire running to that amp?... Thanks forbidden I ll try that

kachud

Yes. The fuse just after your battery will keep your car from catching fire when/if the power line shorts.

Asmoran

Yes, you still need those fuses. They protect the wire and prevent it from burning and catching your car on fire. The fuses in the amp only protect the amp.

Fuses only protect things "downstream" from the power source. That's why you place them as close as you can to it.

Let's say you fused the battery and had the fuses in the amps. You get in an accident (drunk driver hits you or something) and the small wire running to the amp gets sliced and grounded. The amp is now out of the loop, and isn't getting any power at all - those fuses are worthless. The fuse at the battery won't blow until the big power wire is nearing capacity. Before that happens though, the small wire that got cut is going to exceed it's capacity and catch fire. This is why you need a seperate, smaller fuse on each of the small wires.

kirksaeter88

ANother question... Lets say i have a 80A and 30A fuse in my dist. block, What size fuse do i need in my fuse holder by the battery? a 110A fuse?

jstkilntim

You can probably get away w/ a 100A fuse. Your equipment should never reach the 80A/30A unless there is a problem. Just ensure that your main fuse is not rated higher that the rating of your main power wire.