[zzyzzx]

Just connect up a voltmeter and drive around and that should tell you everything you need to know. Personally, I prefer to have one perminently installed in the car:

 

[zzyzzx]

Hey, I bought one of those but I am kinda dumb. Which wires/parts should I wire it to?

It requires 4 wires to wire up the voltmeter. Two for the light bulb (goes on dimmer circuit) and two more for the power and ground (respectively). I simply removed my radio adapter harness and added it to that (with a disconnect, of course). All the circuits you need are there. However if you are good at splicing and don't care all the wires you need are also at the rear defogger switch, right nect to where I put the meter. I just didn't want to splice into it when I could do my soldering indoors instead.

So basically its:
Switched power
Ground
Dash bulb power
Dash bulb ground

Do not use a common ground to simplift it to a 3 wire circuit. I suspect that you will get a hum whenever you turn on your lights, or somehting.

 

[zzyzzx]

"well not a new alternator, but a restored one from SGI"

What's SGI?