How to: wiring connection
 

Anyone here knows how to wire an electrical component without resetting or powering up upon starting the engine? Is there any solid state device to do it? I just want some electronic device connected to my disco to keep running even when starting the engine back again. Thanks - Gerry

Depends
 

What you want to power up.
First, I would check both fuse boxes for an unused source of power, or a place to tap a source of power at all times.
Then, once determined source of power is located ( too keep in mind, what you are powering will also determine locale )
If you are switching something on and off at times, a relay will be of use ( relay is basically a smaller amount of power to control a larger amount of power )
( to picture that, think of your key switch to start - you don't have the big starter wire running through your dash to your key )
I guess, really, I need more info to help.
What are you trying to accomplish ?
There are many scenarios surrounding.

Thanks, What I'm trying to accomplish is to keep a computer on even if I shut off the engine and start it again. I have a computer connected to an inverter. Each time I turn engine off, Ex. to get gas, and start the engine again, the computer losses its power and have to boot up again. Which way to wire it?

OK
 

I am assuming the inverter did not come with more than one cord.
I am also assuming that it is less than or equal to 400 watts and plugs in the cigarette lighter.
Take note of how thick said cord is, and the length of the distance as well.
You can either clip the power wire to the existing cigarette lighter and run the power wire to full time power rather than switched power ( but still fused ).
Or you can get a new cigarette lighter for that and mount it.
Or you can get another length of cord for the inverter to go directly to the battery.
To find full time power, you need either a meter or a test light.
If you have neither, I suggest a meter as that will prove more useful as you learn to use it.
Put to VDC and have the leads in the right place ( in the meter and on the vehicle ). Place the black wire to a known good ground. And with the vehicle off and key out, probe both sides of each fuse until you find one with power on both sides. You should find a few. You want at least 15 amps, but shoot for 20.
I like the re-wiring of the cigarette lighter or addition of another, myself.
I bought an inverter from Radio Shack for 20 bucks on sale and it had both plugs come with. Cigarette lighter and battery direct.
Keep in mind if you go battery direct, you will need a fatter wire most likely. Even my battery direct cable is not long enough to be routed inside.
I would also add a fuse to any battery direct setup.
Hope this helps, let me know if you have any additional question.

Even always-on cig lighter plugs turn off with the starter b/c it draws so much power. You need a power source independent of the main battery. Get a small UPS (Uninterruptible Power Supply - like a surge protector with a backup battery) from an electronics store and hook it up to the power inverter.

How to: wiring connection