My mother board has a odd connector I was wondering if anybody had thoughts about it

Why does the CHA_FAN1 header have +5 volts where the PWM pin should be? I thought that disconnecting the fan PWM pin runs the fan at full duty cycle.

 

It could be for a new type of 4 pin chassis fan.

I have never seen 2 4 pin fan connectors.

 

do you suppose hooking up an standard PWM fan would be a bad idea?

 

Here's the 2005 standard for 4-wire computer fans:
http://www.formfactors.org/developer/specs/4_Wire_PWM_Spec.pdf
Connectors and pinouts are shown on page 19.

I'll speculate that the constant 5v is supposed to operate the fan at a reduced speed rather than using an actual PWM signal, which would take more hardware to incorporate than a fixed 5v level.