I am currently re-wiring my carPC setup and need a bit of advice for safety's sake.

My current setup has two power lines: +12V and IGN w/ a SPST switch on each line to cut power, if needed, from the driver's seat.

I am currently using 14ga wire connected straight from the battery w/ a 15 & 5 amp in-line fuse, respectively.

Because my needs grew, unexpectedly, I am moving up to 8 gauge wiring w/ a distribution block, but don't know how to incorporate an ON/OFF switch as the wire thickness is just too big for the switch I would prefer to use that's easily accessible from the driver's seat.

I've been pouring over the posts in this forum but couldn't quite find the info I was looking for. Your advice would be greatly appreciated.

You're going to have to get a switch rated to handle that much current. 40A rated switches are a bit bigger than your standard SPST switch but once you get a properly rated switch it should be able to connect the 8 AWG.

The other way you could do it is with relays. I can switch a high current source with a low current trigger using a relay.

Here's a good read on automotive relays and how you connect them.<ul><li><a href="http://www.the12volt.com/relays/relays.asp">http://www.the12volt.com/relays/relays.asp</a</li></ul>

Do you need all items in your setup to be switched by a big main switch? Can you just put in your smaller SPST (or even several) downstream of the distribution block and switching only one or several devices? Your distribution block will just become a live point in your car just like heaps of other live points.

Right now, I have my carPC, HD radio, Tire Monitoring System all tied into one node point, which makes taking the PC in/out a real hassle, not to mention safety. I estimate that my total power draw for the system is 131watts. At that load, 14ga is just not sufficient. I also want to provide ability for growth should my power needs increase. I think that 8ga should be sufficient

The dist block will be mounted on a shelf that was constructed to hold all that stuff. On occasion, I do remove the shelf. So I want to be able to cut power to the block real easily and have the wire not remain "hot" while it's not connected to anything.

I will wire everything to make it easy for me to add a total aftermarket installation should I ever decide to go that route. Right now, it's just not in my budget.

The link HIS4 sent is very helpful. Consider which pair of contacts to use - C/NO or C/NC. If you want to have power to the block all the time and kill power to it when you want to work on your gear you might consider using the C/NC pair. Switching on the relay will make switch the contacts over to NO, killing power to your block.

Then you can just open the breaker if you need to disconnect the load. I have a main circuit breaker for my system near the battery but I also have 2 circuit breakers in the trunk (1 in front of each amp). The circuit breaker serves 2 purposes. First it provides protection because the amps do not have internal fuses and second it provides a way to disconnect them without taking down the entire system.

...but because its a computer, I quickly learned that putting a switch to cut power on-the-fly was essential if the system freezes due to a app hang up or a corrupted hibernation file.

I have power &amp; reset buttons in the cabin, but sometimes you just need to cut power altogether.

Terribly inconvinient to have to pull over, pull the circuit breaker and reset.

It's a love-hate relationship.

I have a LED setup to tell me if the power is interrupted and your suggestion will retain that functionality.