Time to buy a new alternator, but which one should I get?

Yep, just when I thought everything was fixed, my jeep dies on me in the middle of the night. Luckily my friend was right behind me and gave me a jump, he actually had to jump me 4 times to get me home. The thing is tho i had just charged the battery the day before so this must mean my alternator is shot. Which makes sense cause its over 21 years old lol. Now napa has a 74 amp for $92.00 and a 100 amp for $104.00. I would love to have enough juice to run a sound system and new fog lights but i dont know how much extra power thats gona take. Any advice?

Extra amps can't hurt...worth the extra $$$. Just my opinion...

I mean really...we're talking $12...really? $12? You loose that much change in a couple of weeks! HaHa

Congratulations--your XJ is old enough to drink in Oregon!

1989 uses a CS-130 Delco Remy, you might consider upgrading to a CS-144. Both the CS-130 and CS-144 have been used in many, many different applications, and can be had "clocked" differently. I would hit the salvage yards and pick up a higher output for cheap if it was mine. CS-144 outputs 140/170/200 amps. Here is some basic info: http://www.alternatorparts.com/CS-144_Special_offer.htm

BTW, the correct way to decide would be to sketch out what you want and calculate what you need.

Take a look at this article.

Boatwrench said:

Take a look at this article.

Click to expand...

The problem there, Tom, is that the article you've referenced seems to be for the 1991-up XJ, with the Nippondenso alternator and the regulator inbuilt into the PCM. Can't directly bolt the ND into the RENIX rigs - no regulator means no output (unless you get creative and manage to wire full voltage to the field coils - that usually means cooked electronics...)

OP - unless you're going to get silly with things, the OTS 100A unit will serve you neatly. If you want more, any competent alternator/starter shop can fix that up for you, just tell them what it's for (although it's easier if you at least take them a case, if not a whole core.)

Joe - I've never actually looked into swapping the CS144 into a RENIX rig - I've got a shop that does rewinds, and fixed me up with a CS130 on a "special" (no, I'm not going to tell you what I get out of it.) I know the CS144 is physically larger - the number refers to the rotor size in millimetres (CS121 having a 121m/m OD rotor, the CS130 having a 130m/m rotor, and the CS144 having a 144m/m rotor...) so I'd like to see how that was handled. I've seen the swap mentioned a few times, but I know it can get a bit tight down there (ask anyone who's gone from a 90A ND to a 136A ND - or higher! - and see what they have to tell you.)

So, is the process of installing a CS144 similar to an upwound/larger core ND? Got a link or a writeup I can have a look at? Just wondering...

I went to an alternator shop and said "gimmie the biggiest one that will fit, and run a wire out of it to override the regulator for onboard welding." That's exactly what they did. They also replaced the avalanche diodes with normal diodes which is also necessary for using it as a welder. It creates a little more radio interference, but them's the brakes.

2 years later and I'm still not using onboard welding. Oh well.

Couple other things to remember:
* Alternators produce rated current at above-idle RPMs. If you're doing a lot of crawling, your 70 amp alternator is probably never putting out more than 50 amps. This is only a problem if you have lots of loads (radios, lights, winch, etc).
* A shop can put a smaller pulley on it so it spins faster at idle. This may cause problems at higher RPMs however. A good shop will be able to advise you on pulley size.

5-90 said:

Joe - I've never actually looked into swapping the CS144 into a RENIX rig - I've got a shop that does rewinds, and fixed me up with a CS130 on a "special" (no, I'm not going to tell you what I get out of it.) I know the CS144 is physically larger - the number refers to the rotor size in millimetres (CS121 having a 121m/m OD rotor, the CS130 having a 130m/m rotor, and the CS144 having a 144m/m rotor...) so I'd like to see how that was handled. I've seen the swap mentioned a few times, but I know it can get a bit tight down there (ask anyone who's gone from a 90A ND to a 136A ND - or higher! - and see what they have to tell you.)

So, is the process of installing a CS144 similar to an upwound/larger core ND? Got a link or a writeup I can have a look at? Just wondering...

Click to expand...

I'm getting ready to do this upgrade myself, but in conjunction with relocating the alternator up top. I will do pictures/write up with it. I have read a couple of posts on the CS144 upgrade in the original location, and at least one mentioned a tight fit to the frame but doable.