simple electrical questions

[hippo]

I want to put some switches in a 93 for lights, ect. If I put a 40 amp relay with the switch do I have to use a 40 amp switch with it. What in laymen terms is a single pole single throw, vs. a double pole double throw. And lastly if the switch says off-on-on is it possible to run to lines on the second one and one on the first. Like if I have four lights but only want two on, but also would want all four at some point. The second on being all four lights.

I think I know the answers, but wanted to be sure.

[Tacoclaw]

On the relay question, no you do not need a high amp switch. The point of a relay is to operate a high-amp load without needing a high-amp switch. You only use the switch to control a small magnetic coil inside the relay.

I'll try to find a diagram or something on the DPDT/SPST :edit: http://en.wikipedia.org/wiki/DPDT

And yes, you can operate different/combined lights with a single switch. It would be a lot easier to use 2 relays to do it, but I assume that's why you were asking about them in the first place.