Wd mypassport 320gb external hard drive not recognized

Ok so I just bought a hard drive that isn’t detected by windows or mac. idk what the drivers file name was before I bought it all I know is that it won’t connect. On a windows machine it makes that sound that something is connecting and says it installed correctly but does not show up in disk manager or my computer. On the Mac it when I connect the hd it freezes for a little like it knows something was connected but nothing shows up anywhere. When the drive is connected to anything the light comes on and the drive spins up. The light flickers extremely fast I’m not sure if its not getting enough power or if it is supposed to do that. Any ideas?

If the drive has an extra lead coming off of the wire connector you may have to plug that into a usb to gain the extra power.