My 86 oldsmobile is making a buzzing noise and it wont stop

My boyfriend was having the same exact problem last night. He walked outside after it had been for two hours and there was a low hum/buzz on the passenger side of the car. It started after he ran through the car wash. He has an 84 Cutlass. He says.. "Check the water in the battery. Put your hand on the starter. Feel for a vibration. Disconnect the blower motor and reconnect it." He had to take the ground off the blower motor, disconnect the battery, pulled the blower motor and replaced it. He replaced the blower motor because it stopped humming when it was disconnected. Hope this helps.