gray strips should be + Red will be + If there is more than two on fan,it is a mutipl speed fan. each color will be a diff speed. Black is -
Just play around with it. 12v dc is safe (no major shocking)
yes if it is a DC fan with the same voltage as the charger. The charger will have the out put on it.
out put correct. The fan will run,just not at full speed.
Why has noone suggested he buy himself a computer power supply and connect the fans to that
Wow waay too much advise on wiring, If you arnt a trained, certified electrician you need to take this to one. If your too cheap for that then your too cheap to grow. PERIOD use ur head!