COOLING FANS CONSTANTLY RUNNING

[BLUETHUNDER]

Can any one help me with this problem.When i switch the ignition on in my car from cold the cooling fans instantly come on and will stay on until the ignition is switched off.I must add that this has only happened during the recent spell of bad weather,where i had driven the car through a flooded road that created a bow wave over the front of the bonnet.I was wondering if this could have caused a short circuit causing the fans to run constantly.Any advice would be most appreciated as i dont want to buy a pair of fans if these burn out.