Ohgary, calm down. You don't need to be so obnoxious.
Which is why I gave 2 propositions: Either put it close to the battery (thus making it difficult to short) or make sure that your cable is securely attached and won't be shorted out and then put it by your device that you're powering.What happens if you short the positive cable anyplace before the fuse? You get a melt down
Not if it's after the fuse. See response #1what happens if you short a positive line with the negitive return line
Funny that. I've used that setup for 4 years now and never had an issue. Also strange how my buddy who works as an engineer at GM agreed with my installation and the way that I did it. I just put a 30A fuse right next to the battery and then ran the cable to the trunk to my amp. If there is any shorts at all, the 30A fuse will blow. I modified this setup to put a second fuse in the trunk so that I could power my inverter for my carputer as well, but really that wasn't necessary.A single fuse inside the vehicle directly connected to the battery is asking for trouble
No, if the line is shorted BEFORE the fuse near the amp, then you have a problem with the battery and wire, but any device attached to that line will be unaffected (current takes path of least resistance). If the fuse is near the battery and the wire is shorted anywhere between the fuse and the amp, then the fuse will blow and there is no problem.The reason for the fuse near the device is to prevent heavy currents during a short from going through the device. If your amp is direct attach to a battery with a fuse at the amp then a short of the ground to a + line will cause a high current flow through the + of the amp through the amp and down the ground line
I think your response is the best response to what you said there:There should be 4 fueses [sic] one on each leg of the power on each side of the fire wall
"most people who do this are fools".
Fusing the negative line is *pointless*. Unless you have done a lot of crappy wiring in your car then you're not going to find any incorrectly fused +ve lines. Additionally most "ground" connections are done nearby the device to the vehicle chassis, so they're not run by any rogue +ve lines anyway. For example I have a screw in my trunk that is into the chassis and that's my ground connection.
Even if, for some unknown reason, you want to run a second wire directly to the -ve terminal of the battery, since the entire chassis of the car is ALSO THE -VE TERMINAL, the only way that you can cause a short is to have that cable itself short out another +ve cable before a fuse. If you're going to run a second -ve cable to the battery, you're most likely going to do that away from any +ve leads anyway. But this is a dead point because nobody runs a 2nd -ve line straight to the battery.
So my opinion remains, you only need one fuse. If you want to be super careful, put 2 fuses, one near the battery and another near the device that you're powering. Note that almost all electrical wiring in the car is single fused, and
no they're not. They're 14-16 guage wires which will melt when there is a short simply due to the current that passes through them. Unfortunately these melts can occur anywhere in the line which makes them a real PITA to replace, thus why fuses are used.many of the "wires" in cars are fuse wires that will break when they are shorted