Computer fan Help

[gabrielle1976]

Ok just for you search people I did a search and I found lots of stuff but I did not find the specific answer to my specific question.
I have a red wire and a black wire on my computer fan , the man at the 2nd hand computer place said the black wire was the ground wire , ??
my question is on my cell phone charger there is a smooth wire and a wire that has a grove along the side , what one do I wire the black wire to ????

Thank you.

 

[daisychick]

Strip the wires down from the charger a little bit and you should see colors on the wires. We had to do the same thing. Then go from there.

 

[KatyTheChickenLady]

on my stereo the groove is the red one.

 

[gabrielle1976]

Thank you.
I got it running lol I could shoot the guy down there .. lol he only charged me 50 cents for it but I wanted one of the ones that were bigger lol and he said they didnt work yeah shure so he sold me a tiny one. It barely moves the air but I figure it will help a tiny bit till I go back and get a bigger one and at least now I know how to wire them.