power supply question

I want to pull out a power supply from an old junk computer and use it to run some neon lights that i pulled out of my car. I think this is possible, because the power supply has a 12v output on the inside, i think it's the yellow wire ? anyway..

i pulled it out, and plugged it in.. nothing.
i read the wires and saw the start wire, i think green? so i connected the positive to that - and then i got a pulse of power to the light... like, one every 1.5 seconds.

I asked around and other poeple have seemed to be able to do it. Is it possible that i don't know what i'm doing? or i asked some of my friends and they suggest that the different power b/w A/C and D/C ... any suggestions.. the next step is to open up a computer and connect to the 12v power on a running computer, and not just a power source all by itself.
If all else fails, i can get a power converter from a home plug to a car, cigerette lighter thing...
Any advice would be helpful, thanks.

- pure -

Usually I just replace power supplies so dont know that much about the inside either but I do know that car batteries can give quite a lot of current, not sure if a PC power supply can...I can imagine PC hardware only using tiny amounts.

Maybe that's why the lights pulse because the capacitors give out burst, then recharge?

There is more to electricity then just the right voltage, maybe you should check some more specs on the neon light and the power supply. (volts, watts, amps)

yeah could be, i just wondered if anyone had every tried or done it, thanks for your reply thogugh! i apprecieate it.

- pure -

you can conect the black and green wire ,on motherboar cable,and your power supply will work with out computer
by the way
black and yelow give 12v
black and red give 5v
blak and orange give 3.3 v

You could also just buy some neons made out of LEDs and run it all of a USB port, much simpler.

Flabby Rabbit