Yeah @Barry it has on off switch but you can make it auto also you just have to throw in some temperature tripping switch that way it will automatically switch on when required and @derik of course its a used fan from a yard where else you can get a fan with brackets for 75 and as for warranty that it works or not that decision we can leave on gaurav Bhai he will put it to test on friday and post here the results....and my opinion is that during climbs the car is usually very slow so not much air passes through the atf cooler and by fixing a fan on top of cooler will force air through the fins which will improve heat exchange that I am sure....