My alternator on my 2000 Police Interceptor recently went out and I can't afford a new one, so I went to a scrap yard since they're only 60 bucks there. All the p71s had their alternator removed already, so I just grabbed one off an 08 grand marquis. I knew it wasn't going to be enough and it's probably going to prematurely fail, but I figured it will do for now to get me to work until I get a check on the 1st. Here is where I am confused though, on this website https://www.idmsvcs.com/2vmod/alternator/modelnumbers/index.html it has a list of the differences in alternators throughout the years. From 98 to 02, it says 130 amp 6G on the police model, but on an 08 civilian/grand marquis, it says 135 amp 6G, yet my voltage is really low. Could I have just grabbed one that was going out? Is there a difference that I'm not realizing?

Read the rest of that article.
02- alternators use a I-Line voltage regulator. 03+ use GenMon/GenCom PCM regulation.

You must use a 02- alternator.

In addition to what Davidzq said, you should know that it isn't necessary to use a higher-amp alternator on a P71 in civilian use. The main reason for the extra capacity is to support all the additional police equipment..radios, lights, computers, etc...and to keep the battery from running down when the car is left idling for long periods.

So it’s a matter of year, not the actual amperage? And I can use one off of an LX/MGM/LTC? I figured I could since there’s no lights but wasn’t sure.

That seemed logical to me but I wasn’t sure. I didn’t want to spend a lot of money and get the wrong thing, you know?

Yes, you can use any amperage alternator. In fact, P71s did not get a larger alternator (200A) until 2004.

You will want a 6G alternator though, so any 98-02 P71, or any 98 civilian model.
99-02 civilian models use a 4G alternator. You can use these if you splice a 4G pigtail onto your car.

Thank you for your help. I found a reman 6th gen for 1998-2002 CV/MGM/LTC models online. I also found a diagram for the visual difference in a 4th gen and 6th gen connector. (The 4th gen is flatter and wide, has a round trapezoid shape, and has a black rear case, The 6th gen is narrower and taller, is rectangle shaped, and the case is the same color all around)



6th Gen


4th Gen