This is the third time since 2004 that this has become a problem. Each time the housing caulk failed (approximately every 2 yrs.) I had to take it in to the dealer for recaulking. Fortunately it hasn't affected the blower motor. The dealer said the water leaking in through the housing could cause the blower motor bearings to rust and cause a failure of the blower motor. Maybe Ford should research a better, longer lasting caulk for this problem.