Need a switch for 8 gauge wire

[Throckmorton]

The toggle switch wire needs its own small fuse.

Also, you might want to run another wire directly back to the battery. Otherwise you can get power that isn't clean, or I guess a bad ground

 

[Throckmorton]

For my offroad lights I drew power for the switch from the cigarette lighter, which went through the switch and to the relay. So when the ignition is off, the switch gets no power.

 

[SooperDave]

I'd go with a continuous duty solenoid. the fifth from the bottom on this page is an example.. http://www.ase-supply.com/Solenoids_s/44.htm

You can use lugs and crimp or solder. I prefer to solder. If you get the copper lugs and hold them with where the wire goes up you can insert the wire, heat with a small propane torch (like they sell at home depot) and feed the solder in until it fills to the top. Heat shrink is always a nice touch too. Don't use too much heat or the insulation will burn also and the solder will chase that copper uphill. The cup will not fill, and the wire gets stiff for several inches past the top.

 

[Howard]

http://www.google.ca/search?client=opera&rls=en&q=crimping+solder+vibration

 

[Rubycon]

http://www.google.ca/search?client=opera&rls=en&q=crimping+solder+vibration

Again I base my recommendations on experience with soldering lugs on large line array subwoofer systems. I could not think of an application that would have more vibration. Failures = 0. Yet I've seen plenty of failures with (non soldered) connections.

 

[imagoon]

I told you to use a relay when you first started this...

Anyhow, your diagram looks fine. YOu can switch either the hot or ground side and it will turn the inverter on and off just fine.

The toggle switch can be connected to a different power source such as the cigarette lighter if it makes it more convenient. What you are switching is a coil inside the relay which causes the switch to throw and power on the inverter. Bosch type automotive relays are usually around 75 ohms so that's less than 200mA that you need to go through the switch.

For safety reasons you always switch hot (+) in a negative chassis ground. Reverse is true in a positive ground car (rare).

A ground short in a switched ground may power things up that shouldn't be or start scorching wires in a way that won't pop a fuse on the positive side. (ever wonder why all the fuses are on the (+) ?)