new antec chassis fan not working

dopemoney

Distinguished
Feb 7, 2014
70
1
18,645
so the fan came with 4-pin molex and 3-pin header connections. motherboard has 4-pin headers. when connecting the fan via mobo (sys_fan3), i get nothing, no spinning. when connect to psu of course i get full throttle. when connect fan to header and psu, fan is full throttle and BIOS will read fan speed properly. why wont fan run if only connected to mobo alone? fan headers are enabled in BIOS and set to .75pwm / C. which my understanding means that at minimum fans should spin up right after boot, no?
 
Solution
thanks again. i got it figured out. so there was a splitter that came already attached to the fan, probably for the 4-pin molex connection. the fan without the splitter is still a 3-pin connector. when i removed the splitter and connected straight to mobo, fan spins up and is properly controlled with rpms being read as well.

dopemoney

Distinguished
Feb 7, 2014
70
1
18,645
thanks again. i got it figured out. so there was a splitter that came already attached to the fan, probably for the 4-pin molex connection. the fan without the splitter is still a 3-pin connector. when i removed the splitter and connected straight to mobo, fan spins up and is properly controlled with rpms being read as well.
 
Solution