I've been taking Jays2cents advice and setting up Fan Control which is going great but there's a massive whole in my knowledge. Anyone who has used Fan Control https://github.com/Rem0o/FanControl.Releases on an ASUS motherboard will no doubt see a list of 6 sensors. I want to know what they are.
I have 6 fans in total 3 at top AIO 2 on the side. It would be nice to know which area of the motherboard they pertain too. At the moment I've just mixed them but no idea which fan can reduce any of them. Two of them report crazy temperatures over 100C which I've learned indicates open circuit as in not in use. Another sits at 15C which I find very unlikely. Another is constant at 32C. Going into Armoury Crate and Temperature sensors I can't readily match them it's pure guess work as nothing is close enough.
If you check this article out in it there is a picture https://www.cgdirector.com/motherboard-temperature-guide/ out MSI do at least a diagram to show where they are. That's ideally the kind of thing I'm looking for.
Any help would be appreciated.
I'm not aware that the guide you want is available, but if you find it, please let us all know. All I know is that on the 690 Hero, sensor #2 is the 'motherboard' temperature. At least, that's the one I monitor in HWInfo as the closest thing I can find to a temperature that corresponds to ambient temp inside the case. I use that one to control my case fans in iCue. I also assumed the same as you, that crazy temperatures like 100C and anything below room temperature are just open circuits.
If you look at the temps indicated by FanControl and then compare with HWInfo, you might be able to get some clues by matching the live temperatures. Just be aware that the temps can be slightly different depending on how often the temperatures are updated, so you might need to watch them for a while to be confident that you have identified the right ones.