If you alternator is truly flucting after using a voltmeter. I suspect the voltage regulator is failing. It is mounted on the back of the alternator and is easily changeable without removing the alternator. If you elect to remove the alternator, the bottom bolt will be corroded in the aluminum hole and will require considerable effort to get out. Once loose the bolt will slide very tightly next to the radiator fan shroud, but will come out with effort.
You have already been given good advice on your charcoal canister.
Richard
