Hi,
My 97' dodge grand caravan has this issue. The battery quit working, so I got a new one. Now when I connect the new battery, the radiator or something loud turns on like some type of fan. The keys are not even in ignition... Just the battery connected triggers it.
While this is happening I can still start my car and drive it, but it's just awful because when I turn car off I have to take negative wire off battery. Please helppppp.