i rqn 8 gauge wire to my trunk dirrectly from my battery to my 750W power inverter which has two 50 amp fuses. i want to install a switch by my dash so i can turn the inverter from the front of my car instead of going to the trunk to do it. do i need a hundred amp switch.

 

Think of it this way:

You want your fuses to blow before you switch does in the event of a failure. So yes, I would do a 90 to 100 A swtich.

 

That's a seriously big switch. Where are you going to mount it?

 

better question is....what are you going to plug into it?
your computer?

 

I'm thinking a toaster or maybe a hairdryer.

 

i am plugging my computer into it

i was gonna get the Hella Contour Master Power Switch
http://robotcombat.com/marketplace_switches.html

 

Wouldn't putting in a relay be easier?

 

what would a relay do. exuse my lack of electrical knowledge.

 

A relay is basically a remotely operated switch. You can use a small switch on your dash that sends a signal for the relay to open or close. It would look a lot better but it would cost a little more.

 

how much more would it cost the switch i found is $22 so if its not gonna cost me like $60 or $70 i would be interested in seeing this contraption.

 

You should be able to do it for less than $50.

 

Here's an example of what you're looking for: http://tswf.com/TIE/relays.cfm

Scroll down to model 24200 (4th one down)

If you want to know how they work, here's a good article: http://electronics.howstuffworks.com/relay.htm

 

Wouldn't you think SP BRK30 from the first links works better? What you really need is to turn on/off the DC power going to the inverter. Radio Shack should have plenty of automotive relays.

 

I would say that would be fine for 99.999% of most car uses but he wants a switch that can handle 100A or 1200W. I don't know what kind of alternator he is going to install because I know the stock one can't put out that kind of power but I'm just answering the questions asked....

 

Ah, I see. Damn, that's a lot of power.

 

Well I have an inverter that does not run at full power unless it is required to use that much power so it really only runs at 50 amps which is on one plug and its a computer drawing 250W for the power supply

 

Have you considered a laptop computer? It would require a lot less power.