Topic: Alternator upgrade

[que89yj]

I am working on my 89YJ 2.5L and I am looking at doing the fan upgrade. I have searched all the posts for the fan and alternator upgrade and I am wondering if the alternator on my 89 is internally regulated or externaly regulated? Does that limit which altenator I can put in? I read the post and it seems kind of vague with refrence to the early 2.5L, but both the later YJ rail fuel injected YJ's after 91 I am sure both were externally regulated through the PCM.

[Jeffy]

Your choices are right here

IIRC, there was something about the CS-144 that needed to be addressed but I don't remember what it was.

[chardrc]

sorry to bring up na old thread.. but did the electric fan upgrade and need to get bigger alt to keep the battery happy. do you know where to find what would need to be addressed with the cs-144 nothing is mentioned in the other thread about it needing modification. would be nice to be confident in forking up the extra $ for the 140A instead of the 100A and know it will work.. thanks

[jfrabat]

sorry to bring up na old thread.. but did the electric fan upgrade and need to get bigger alt to keep the battery happy. do you know where to find what would need to be addressed with the cs-144 nothing is mentioned in the other thread about it needing modification. would be nice to be confident in forking up the extra $ for the 140A instead of the 100A and know it will work.. thanks

I ran the FoMoCo fan with the stock alternator on my YJ for about a year with no major issues; but I did use the Delta Current Controller to control the speed, which means it would not pull as many amps as it normally would because of the soft starts...

Later, I replaced the alternator with a Load Boss 167A (IIRC) that I found on eBay for about $140 or similar...  Complete bolt in, with no mods necessary.  For your reference, I run fog lights, H4 lights, AC (believe it or not, the AC fan pulls more amps than the FoMoCo fan!), 100W daylighters, sound system with Amp and SW, CB, GPS, and I have no issues with the battery.  I do plan to replace the old battery (has about 3 years on it) with a Yellow top before I leave, but that's just for the peace of mind that the battery will not die on me anytime soon...

[chardrc]

well after installing the fan i found 2 things with my jeep. one the thermostat is shot (doesn't open tell temp gauge (that i finally fixed) is in the red). and when i idle for an extended period of time the computer tries to lower the rpm too much and it sputters a few times and rebounds before finally going too low and dieing. my jeep would sometimes hickup at idle (probably becasue it doesn't get driven enough) but i think the extra pull form the alt could be messing it up now... my current alt is 78A and im basically trying to decide weather i should go with the 100A or 140.

[jfrabat]

my current alt is 78A and im basically trying to decide weather i should go with the 100A or 140.

If you are going up, go up more than to 100A...  I would go to 140A.  Better to have extra capacity than not enough...

[chardrc]

i think imay wait on the alternator for a while.. got the new thermostat in and now it doesn't try to overheat all the time... and the idle is better.. ill put some decent miles on it tomorrow to make sure im not kidding myself. but at the moment im happy.