Hyundai Accent Parasitic Drain. Please Help.

Hi,
My wife's 1996 Hundai Accent has a parasitic drain when the car is off but only when the car is hot. It will continue to drain once the engine has come to operational temperature for about 1-2 hours until the engine cools off. It drains at a rate between 2-3 Amps. When the IGN fuse is removed, the drain stops. Also, there is a strange buzzing sound coming from one of the sensors attached to a branch of the air intake. When unplugged the buzzing stops but the drain continues.

Does anyone know if the alternator is on this fuse? What is the most likely cause of this drain and why would it only drain when the engine is hot?

Thanks,

David