So I was thinking about replacing the alternator on my 1990XJ, But most of the walkthroughs are for 1991 and up, is the renix electrical system just not a good candidate for a more powerful alternator? Thanks guys.

 

You can go up to a 100a alternator in the stock bracket (higher if you mess around with the alternator internals). If you grab an alternator bracket from an h.o. Your options drastically increase. You will also need a voltage regulator as I don't know of any internally regulated alternators that will fit the h.o. Bracket and renix style plug.
I am running a 136amp alternator with h.o. Bracket and vr166 in my renix. Could even put in a stock 200a alternator from a Dakota.

 

Have one custom built.

I called a shop yesterday for an alt for my MJ...........$1.00 per amp.

He said he could get between 150 and 170 amps out of a stock GM alt such as yours/mine.

 

If you don't upgrade the cables first, you're wasting your time. www.kelleyswip.com.

 

Thanks guys I really appreciate the info.