Might go for one of these, will allow all five case fans to go off one PWM header but molex power.
Image fan hosted in ImgBB
ibb.co
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Sleeved PWM Fans Extension Power Splitter Cable,Connector 4 Pin Molex or SATA to 3 4 5 6 Way 4Pin Fans Spliter Power Cord for Motherboard PWM Header
Power from PSU Molex 4-pin or SATA 12V DC, supporting up to 6 PWM fans from a single motherboard header
PWM 4-pin female connect to motherboard for RPM feedback,allowing all fan speed to be synchronized with CPU load
Compatible with 4pin PMW fan connector and 3pin fan connector (Due 3pins no PWM controller, 3pin fans would run in full speed.)
Power from PSU 12V DC only,do not utilize for 5V DC fan
Sleeved in a black is enhanced cable management,enclosure to provide a sleeker look that seamlessly integrates into the case's interior
Note:
Since only one RPM signal can be read by one motherboard connector, only one 4 TIPS CONNECTOR of the fan splitter cable carries an RPM signal. Thus the motherboard will only read the RPM signal of the PWM device that is connected to full 4-pin connector.
The other four male connectors are missing the pins of tachometric signal,ensure your fan speed monitor won't bounce all over the place from getting three sense signals.Guarantee motherboard getting an accurate RPM signal.
Only one of fans sends its tach signal (the one with full 4-pin connector) reports its RPM, but the others will still follow the PWM signal."