Here I will explain the purpose of the flow switch on my computer. The Johnson Pump CM10P7-1 requires a 1.6 amp fuse, if the fuse burn, and without the flow switch protection the computer will suffer a terrible death.
When I started my project I had the Asus PT4533 motherboard, with this motherboard you can actually disconnect the CPU fan cable from the motherboard and the computer will stay on :shrug: , not all motherboards have the same glitch, but from what I learn reading on the forums, there are a lot of them out there with this problem.
After I got everything I need it to protect my computer from a possible disaster, I decided to get a new motherboard (I have a friend that wanted to buy my computer, so I sold it to him
), I got the Abit IC7-MAX3, and to my surprise this motherboard actually shutdown in 1 sec. after disconnecting the cpu fan cable (making things more easier)
There is also a cheaper way to prevent the computer to say on if the fuse burn, just use the same +12v DC pump cable after the fuse to supply voltage to the fan, if the fuse burn, pump stop, fan stop (no r.p.m. signal to MB), and your computer will shutdown, but it wont shutdown the computer if there is low flow from the pump.