how do i know when using an ohm meter how to tell wich is open circuit for power and wich is ground? thank you

Can you restate you question? I'm not sure I understand. Are you trying to find out if a wire has power or is a ground wire?

EDIT: Or maybe with the battery discounted you're trying to determine if it's power or ground?

Or maybe some instructions on how to use a meter. The sections here on voltage and continuity may be helpful.
http://www.shadetreemg.com/multimeter.htm

trying to determine what wire is what wire from my turn signal they were melted apart causing one light to be dim and not activate when the blinker was on and whwen i removed the plastic connector the came out real fast and im trying to determine wich is ground and wich is power as the gas gauge was also affected by this problem . i was told i could use an ohm meter to see wich is power and wich is ground on the lead wires and on the blinker lead wires. hope that helps
thanks

I don't know what year you have. Assume you are looking at the long turn signal connector on the top of the steering column.
That connector has no ground wire in it. Ground comes from the car's sheetmetal.
Purple should be the turn signal 12 volts
Green and yellow are the outputs to the rear bulbs.
The 2 blues are the outputs to the front bulbs.

the wires coming outta the turn signle at the front bumper and they both look black to me they come outta the bulb socket

Would you like to tell us what type and year car your working on so maybe we can help you a little better.

70 chevelle

Well, it's a 70 or earlier. Probably can see the colors if you look on the other side of the connector closer to the frame. Brown and blue would be a good guess.

okay that problem is solved thanks guys