installing a electric fan to a toggle switch

If street driven, I would hook up sending unit to turn on auto. Someone WILL forget to turn on! Rocker an relay should be fused! or rocker can switch/ground of relay

 

I used to have my fan on a toggle, worked good till I forgot to turn it on when I needed to (letting the car warm up while I was talking to friends in a parking lot, conversation went on longer than expected) and ended up spewing antifreeze all over the ground. sents then I've installed a temp switch, much better. just my 2 cents. btw the temp switch was about $10 to $15 from autozone or checker.