Often, a failing alternator, doesn't mean you have to replace the whole unit. You can replace the regulator/brush combo for less $.
However, I would first suspect a loose contact - check your battery cables from one end to the other, and perhaps the battery posts themselves, before replacing parts.

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It is a truism that almost any sect, cult, or religion will legislate its creed into law if it acquires the political power to do so. Robert A. Heinlein


09 Jetta TDI
1985 300D