Thread: Wiring from battery and switch questions

i don't have the computer hooked up to it, i definately am going to put fuses in, but ive had the wire for a few weeks, its 10 feet , lol more chances to start a fire! yay

I would think a relay is a better idea so that you don't pick up any stray signals on a long length of wire.
Best regards,
Matthew

Originally posted by Telek
Aaron: Why do you say that using the relay is a better idea for your reset and power sw? I'm just running a length of wire and put a switch on the end (I'm using ATX) and I haven't had any problems.

Thre's a whole bunch of reasons that I can think of:

1. Prevents interference
2. In case of short, just blows a fuse instead of possilbly killing a motherboard
3. Allows control from many different points
4. More "standard" (ie...apply 12V and it turns on, remove 12V and it turns off)
5. Less cabling and connections required
6. For power (I am AT, not ATX) eliminates high current wiring through the dash for power switch (safety)

Originally posted by Aaron Cake
Thre's a whole bunch of reasons that I can think of:

1. Prevents interference
2. In case of short, just blows a fuse instead of possilbly killing a motherboard
3. Allows control from many different points
4. More "standard" (ie...apply 12V and it turns on, remove 12V and it turns off)
5. Less cabling and connections required
6. For power (I am AT, not ATX) eliminates high current wiring through the dash for power switch (safety)

Actually the only point that I can see is #6.

If you're just running the leads for the power and reset headers on the motherboard for ATX, it's kinda difficult to short something out since it's designed to be shorted in the first place (that's what completes the circuit). Unless you somehow manage to short it to a live +12V I guess.

#1,3 aren't really important if you're just running a power switch.

#4,5,6 are really only valid if you're running AT and not ATX.

Oh well, in any case, I've been looking for a simple circuit to turn on/off the ATX power because $33USD + shipping + duty (probably close to $70CAD) is a little expensive (IMHO) for just a simple thing that can delay and then issue a pulse to the ATX power header after the ignition has turned off.

Since your inverter has built in fuse protection you really only need a fuse at the battery on the positive terminal. I have done many installations this way. It's how everyone does them. If you wire it properly and you use a gromet when passing through the fire wall you should never have a direct short. And always, with any wiring, when you've got it all hooked up, ohm it out before applying power. When you're sure you have no shorts then turn on the power and check you're voltages. Then you're done.

yeah this is what most of us have concluded already

I think #1 is very important. Those headers were designed for short leads in a well shielded PC case, not 10 foot leads in an electrically hostile car.

Another plus is that it allows easy control from a head unit's remote line.

I am Mecp Certified Master installer with more than 12 years in car audio. A power supply line needs 1 fuse unless you are running a large gauge wire (above 8) into a distrubition block and then you need to put an inline fuse for each of the lines out of the block NEAR the unit it's self. the point of puttin the fuse near the battery is due to the point people forget there is a constant flow of current thru the cable and if the cable is shorted it will blow the fuse. if a short occurs anywhere in the line path the fuse will pop does not matter if its at the beginning or end. 4 fuses inline is redundant its not going to stop the short from gettin to the amp/computer/ etc if it falls between 2 fused points all that will happen is one fuse will pop not all 4 so the 4 fuses are not necessary, Also you never need to fuse a ground line as a car runs on a direct ground system any metal area in the vehicle is a ground so you would have to fuse the whole car to stop a spike thru the body of the vehicle. If you want to put 2 for your own piece of mind put one at 18" from the battery terminal then within 12" of the unit itself.

Hope this helps

The Batfan

how does the opus look. i know i had an inverter that blew its fuse and that sucker was soldered in there good. just to keep in mind. id put a fuse on the wire.