I'd run 2 fans on 2 separate circuits. One that has to be on while the motor runs and the other manually. No fancy relays. No toggle switches that are not waterproof or face upwards for rain to sit in. A good gauge and a warning lite. And a burp port at the highest point of the top rad. hose, if you have a low mounted rad. Remember , trapped steam does not cool or pump, but it does push your reservoir water out on the ground without you knowing. Feel the top hose on the radiator. If it is cold, there's no flow. Now squeeze the hose and rev the motor. It should always inflate. No inflation means you have cold air or steam trapped. Always rock hard and hot, and ya got trapped steam. Top off your water thru the burp port and you will know you have all the water out. Basicly depending on how what is mounted where, look for trapped air. I have 1 smoked Passat motor because I did not know these things. Another one smoked because someone put too much RTV on the valve cover and oil pan and the residual rtv went straight to the oil pick up screen. 9out of 10 accidents are caused by people. 9 out of 10 people are caused by accidents.