* The alternator itself: The amperage rating is usually stamped directly on the alternator casing.
* Your vehicle's service manual: This manual will specify the correct alternator for your specific Intrepid model and will list its amperage rating.
* A parts store website: Websites like AutoZone, Advance Auto Parts, or Napa Auto Parts allow you to look up parts by your vehicle's year, make, and model. Search for "alternator" and the specifications will often include the amperage.
Without knowing the exact engine and options of your 2001 Intrepid, it's impossible to give you a precise amperage. Expect it to be somewhere in the range of 80-140 amps, but that's just a broad estimate. You *must* use one of the methods above to find the correct information for your vehicle.