voltage regulator

How do I determine which alternator I have on my 2002 VW Jetta Wagon TDI...90 or 120 amp? also, can anyone reccomend a good website or maybe a NAPA part number for a replacement voltage regulator for the same car? Thanks.

I think the manual transmission equipped TDI's have the 120 amp. alternator due to the three extra GP's(coolant glow plugs).
Seems I read that somewhere, but don't quote me.

It says plainly on the Bosch alternator label what the amp rating is.

Problem is that a number of manufacturers made alternators for the A4 cars. You have to figure out which one you have to buy a voltage regulator.