How to connect case fans to the motherboard?

Molex to 4 pin fan header

https://www.google.com.ph/?gfe_rd=cr&ei=8vQhWIeLAuzN8geevK6gBg#q=molex+to+4+pin+fan+header

You need adapters that will plug into a mobo male fan header and accept a male 4-pin Molex plug from your fans. I cannot find such an item, nor a way to create one by simply connecting others. The only way I know is to make one yourself. You need a Molex splitter like this to start

http://www.newegg.com/Product/Product.aspx?Item=N82E16812423186&cm_re=Molex_splitter-_-12-423-186-_-Product

That gives you two 4-pin Molex female output arms that can accept two Molex male connectors from your two fans. Then you need to get a simple 3- or 4-pin fan extension cord like this

http://www.newegg.com/Product/Product.aspx?Item=N82E16812423170&cm_re=fan_extention-_-12-423-170-_-Product

From that you snip off the male (with pins) connector, leaving you with a cable that terminates in a female 3-pin fan connector that can plug into a mobo header. At the end of that cable strip back a bit of the outer sleeving to get access to the three wires inside. Fold back the YELLOW wire and tape it - you will not use that at all. Strip a bit of the ends of the RED and BLACK wires. Next, on the Molex connector adapter, cut off the male (4 recessed pins) connector, leaving you with two female connectors each with 4 wires attached. At the female connectors, snip off the RED lead, leaving one Yellow and two Black on each one. Now, take those two Molex connectors and twist together all their BLACK leads with the BLACK lead from the fan cable and solder and tape them together. Now take the two YELLOW leads from the Molex's plus the RED lead from the fan cable, twist them together and solder and tape. All this will connect the Black Ground leads together, and connect the Red + VDC supply lead from Fan Header Pin #2 to the Yellow +12VDC line of the Molex connectors.

HOWEVER, before doing ANY of this, you NEED to know whether or not your mobo can control your case fans. Those fans can only be controlled by a fan header that uses Voltage Control Mode, and NOT by one using PWM Mode. To help figure that out, post back here the exact maker and model number of your mobo so we can look up its manual and advise whether this can work.

IF it can work, be aware of another factor in this. Fan speeds can be displayed for you only when the fan sends a speed signal to the mobo on header Pin #3. Your case fans, with their 4-pin Molex connectors, VERY likely have only two wires from each fan to its connector, and they do NOT send out any speed signal. Hence, your mobo will never be able to tell you what those fans' speeds are. They also will NOT be able to monitor those fans for possible failure. Fan failure monitoring is based on the speed signal and many mobos will send you a failure message when the fan on the header does not provide a speed. If you know (as you would in this case) that such a failure is false, on some mobos you can instruct it to ignore the fan speed signal and NOT send out any warnings of failure.