What can I do to clean corrosion off of my alternatore

Hello, wow -- that's serious. If the alternator is not working anymore, you'll have to replace it. However, it will not prevent the vehicle from starting in then first place. The battery may be discharged, preventing it from starting -- so check the battery first and ensure it's fully charged and able to sustain a load. Then it will also be possible, once then vehicle is started, to check the charging system output to see if the alternator has in fact been compromised. Alternatively, if the engine cranks and cranks without starting, both the battery and alternator are not a concern, and there's an engine performance problem. Since I can't tell by what you wrote, I advise both ways -- testing will be required if this is the case. www.repairpal.com/repair-shops