Hmmm, I do electric on vehicles that don't go in water all the time, mainly because I hate fan clutches and believe in my head that the power loss from the additional load on the alternator(as long as it doesn't max out the alt.) was less then the load the mechanical fan placed on the engine. But you could always install a master switch to turn off the fan for water crossings and still have it set up with a thermostatic on-off and variable speed.

 

remove your fan and find out exactly how much it helps. Not much untill its hot outside and not really any if your moving.. The electric fans only turn on when you want them, even then the load on a alternator has to be more efficient. Your turning that fan [even if it is slipping] while your cruising 30-70mph. Completely unnecessary. And last but not least. Less wear on water pump

 

That's exactly why I do it. It never occurred to me to turn it off for water crossings.

 

So from what I gather you guys are setting these up with a thermo switch. Where are you placing them? Ideally it should be on the lower radiator hose or on the radiator itself correct?

 

Well, Thermo switches are adjustable, so you can adjust them. Just. Saying

I'll prolly just run
Manualswitches

 

All the thermo switches I have used are preset to engage at a specific temp. Dual thermo will have a low and high trigger. IE 4 wire thermo switches.

Of course I am referring to what I have used most of my life which are on VW/ Audi's

 

Well the 35$ flex a light is adjustable

 

heres alittle info http://www.cameltrophy.co.uk/history/1985.htm

 

You can get kits to 'tap' into your existing ect signal wire or install an additional ect on the head or block and use a control module to toll the e-fan when to turn on, off, and to have a variable speed.(spins slower at low temps on up to max speed for max cooling.) Then you can add a master on-off switch for water crossings if you wanted to.