To get the fan sensors working (with system temp plugin) on the Vision G (and possibly other boards),
sensors-detect
Answer Yes to everything. With luck you'll see in the middle of all this,
Trying family `ITE'... Yes
Found unknown chip with ID 0x8688
Add to your go file (/config/go on the flash drive). This forces the 8688 to be recognized as an 8628
modprobe it87 force_id=0x8628
Reboot. You should have fan speeds showing once you de