Actually, if you are powering fans from a Molex connector, only 2 pins are required - +12 v dc (red) and Ground (black). The yellow wire on a 3-pin fan connector is the speed signal feeding back into the mobo so it can be monitored by the BIOS. But if you're not connecting to mobo, nothing will use that speed signal and it does not need connection to anything. For those fans you cannot connect to the mobo pinouts, if you're using a fan controller with 2-pin output connectors, just plug them into the fans' 3-pin connectors so the yellow is NOT connected. Or, use jimishtar's suggestion and get the right adapters to connect to Molex for uncontrolled full-speed operation.