If your alternator is having trouble starting on its own, there are a few things you can do to try and get it going. First, check the battery to make sure it is fully charged. If the battery is low, charge it up and then try starting the alternator again. If the battery is fine, then check the connections to make sure they are all tight and free of corrosion. Finally, if all else fails, you can try self-exciting the alternator by running a jumper cable from the positive terminal of the battery to the field terminal on the alternator. This should get the alternator started and running on its own.