Anyone know what kind of signal is sent via the remote-on lead to an amp?

I just got a new car (it's a hooptie), and it has no stereo (see hooptie statement). I need some sort of sound, and since buying a new deck for the thing (or even having an old one installed) would be about 25% the price of the car itself, I was thinking about rigging up something sans deck to play from a portable radio or ipod. I've got a pair of speakers and an amp sitting around, but when I was talking with a guy, he brought up the issue of turning the amp on. He thought I'd need a deck. I'm thinking I need a $6 switch from radio shack and a little creativity.

 

Turn on could be used with whatever. Say you would run a wire to acc, than the amp would turn on when ever the key is on acc. It has nothing to do with the headunit, it just need a signal for it to turn on. You could use sometype of circuit or switch or just tap into a wire than turns on when the car starts.
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12 volt source to a switch to your amp! Most turn on signals from headunits are not a full 12volts.

 

That's a pretty easy hack. I was just wondering if it was standardized (like, say, a 5v signal or something), and so maybe I didn't want to run a 12V straight to it, but it looks like that's the plan.

Thanks guys! Soon the hondooptie will have sound again