Alternator Recommendation

[Manche757]

I had new factory ac put in an 89MJ , 4.0 (it just turned 90K miles) that never had ac.  Before having that done, I had a larger battery installed.  I also asked the CC if I would need a larger alternator.  The consensus was maybe not.  Readings on the existing alternator were long blurred away.  It was thought that if the alternator failed, it would not do damage if it did.  With that knowledge, I did not replace the existing alternator.  I had no trouble for over a year and a half.  Now with the coronavirus I drive the MJ on short trips of less than 10 miles and that is not adequate to keep the battery up.  Soooo, I am going to replace the alternator with the biggest output available but I understand that there is a space issue with a bigger one.  A couple of years ago, the following alternator was recommended.  Is this still good and up to date information?  Notice the link states it is for a 2.5 (unknown if that same one fits a 4.0) Also, evidently some wiring might need to be up sized?

 

 

You do not need a voltage regulator. 

New 4g wires, including your charge wire.

Use a Megafuse.

 

Your mechanic will likely need to reclock, reason is shown here-

https://www.summitracing.com/parts/pwm-58137/applications/year/1988

 

 

[fiatslug87]

I've heard Mean Green are good, but expensive. https://www.mean-green.com/1987-1990-40L-242-MG7902.htm

[Manche757]

The mechanic said he spoke with someone he uses that rebuilds alternators to have increased capacity.  I raised the issue that someone here had investigated that but the housing was not large enough.  Will see how this goes.

[ghetdjc320]

Mechman, singer and dc power all make great alternators. I use a Singer but the 91+ use a hairpin style alternator. Powermasters are Hera are good also but had much lower idle output than what I wanted

[benjy_26]

It's not as sexy as a high output alternator, but maybe you just need a trickle charger.