interior lights won't turn on, exterior won't turn off
 

My friend has a 2008 minicooper with 4,400 miles on it. The interior lights won't come on and the headlights won't shut off unless he manually turns them off. He washed the car in very cold weather the other day and I'm wondering if some water could've got caught or frozen and created some problems with the system. Has anyone else had this problem? Can anyone offer some suggestions on how to resolve these issues? The closest dealership is in the next state and he can't get an appointment until january 2nd.

Thanks.