help me half-assed get my indiglo's to work.

okay, so i have some apc gauges for my 89 civic si, they look great!, the only problem is that the little wiring harness(has a pos/negative contact only on it) will not plug into anything. im going to assume they are originally for a 92-95 civic. the gauges were in the car when i bought it, but will not light up... i dont have the fuel/temp gauges, just the tach and speedo. my question is, how can i hook these 2 gauges up to another power source that wont fry them. i had them hooked up to an old toggle switch powered from the cig lighter, but it doesnt output enough power to light them up decently(could be just that switch).

the best solution would be to tap into the wiring harness for the original gauge light. if anyone knows exactly which wires i can tap into on the harness that would be great!

thanks in advance for any help :)