What kind of noise is it making? Motor squeal?
I've got an old 1990 RV and my blower motor in my furnace started to squeal. I removed the furnace and pulled it apart until I got to the motor. But, I could not easily remove the motor as there were pressed-on parts (could not remove squirrel cage fan). So, I set the unit on end and dribbled oil on the motor shaft so that the oil would wick down the shaft into the sealed bearings. I then flipped the motor over after a day and did the other side. Put it all back together and it has been silent after 2 years.
If it starts to squeal again I will just repeat the above.
1990 Winnebago Warrior. "She may not look like much but she's got it where it counts!"