I've recently had a nice little Front end collison. This broke both the radiators, the crashbar/crossmember and the bumper. Since the accident I've replaced the radiators and the crashbar/crossmember thingy. The car starts up fine and there are no leaks in the cooling system etc.

However the problem I am having is that the fans on the radiators keep turning on for a few seconds seemingly at random. Does anyone have any ideas on what could be causing the problem apart from obviously the fact that I've had a crash.