yeah wrap it up with insulating tape but those fans have 3 wires the yellow wire is for revs per minute (rpm) which is used inside the pc to control the fan speeds so if you are gonna wire this baby up to a 12v dc adapter pnly use the red and black wires
on the adapter you will see that the 2 wires are black but one of them will have markings on it which will be lil white lines this is the wire you will wire to the red wire on the fans and then you will be ok
let us know how it goes m8
hope this helps cheers