Alternator differences?

KinesthesiaDrums

NAXJA Forum User
Location
Minot, ND
hey guys....yea, i searched...

so, i just bought a 1999 Limited last weekend to eventually replace my 1990 Laredo.
i have a Mean Green alternator on my '90 that i just put on a couple of months ago....i wanted to swap it to the '99 like i plan on doing with everything else....BUT, as far as i can tell from researching stock alternator part numbers and such, there were 3 different alternators offered for the I-6 XJs through the years... 87-90, 91-98, and 99-01
so, does anyone know the difference between my 1990 and my 1999? is it just the wiring plug?
could i cut the plugs off the stock wiring and solder back on the other jeep to go with the alternator swaps?
or is it deeper than that? like mounting bolt locations, inside wiring, etc.

i haven't had a chance to crawl under my '99 to even just eye-ball it cause it still has that stock "leather underbody" thing on it, and since this day-light savings time crap, i didn't get home before dark....

thanks guys =D
 
won't work.

The volrtage regulator circuit is completely different. The 99 has the voltage regulator as part of the PCM.

the mount is also comp-letely different.
not much interchanges from renix to anything else.
 
thats what i was afraid of.....
damn...i didn't want to fork out the cash for another mean-green, lol.

thanks tho!
 
just get an alt from a ZJ V8. they are 136a I think. easy swap.
 
1984-1986 - Delco SI (Internal Regulator)
1987-1990 - Delco CS-130 (Internal Regulator)
1991-up - Nippondenso. (External Regulator in PCM)

Apparently, there is a change in the mechanics of the alternator (how the wires hook up and are routed, more than anything else) between the 1998/1999 model years, but you should be able to swap back and forth across that line.

N.B. - if you upgrade your alternator (a practise I heartily recommend, especially if you have a good deal of electronics and/or extra batteries and/or a winch...) note that you should also upgrade the fuse protection in the alternator circuit. The OEM fusible link/fuse is sized for the OEM alternator - if you run your uprated alternator at full output for more than a couple of seconds, you'll blow the fuse. This is not a fault of the alternator - and it can be avoided simply by "finishing the upgrade job" by making sure the circuit is protected at a higher level. Also, you're going to want to upsize the alternator output lead (at a minimum) for similar reasons. It will take longer to overheat the lead than it will to blow out the fuse, but it's still a hazzard that should be addressed as part of the upgrade.
 
thanks guys...
i might look into that ZJ swap...but i really like the 200amps that the mean-green dumps out....BUT, i plan on adding a second Yellow-Top and i already run capacitors for my stereo amps.....

i never even thought about upgrading the fuses.....damn, that should be a no brainer, haha. where are the alternator fuses on the 99's?? (i don't know jack about the differences after 97 yet, and don't have a FSM or Haines yet)

i upgraded all the wiring to at least 6ga on my '90 and plan on doing the same to my '99....so don't worry about that one, haha

oh yea, i <3 Jill Kelly as well, haha
 
Last edited:
KinesthesiaDrums said:
thanks guys...
i might look into that ZJ swap...but i really like the 200amps that the mean-green dumps out....BUT, i plan on adding a second Yellow-Top and i already run capacitors for my stereo amps.....

i never even thought about upgrading the fuses.....damn, that should be a no brainer, haha. where are the alternator fuses on the 99's?? (i don't know jack about the differences after 97 yet, and don't have a FSM or Haines yet)

i upgraded all the wiring to at least 6ga on my '90 and plan on doing the same to my '99....so don't worry about that one, haha

oh yea, i <3 Jill Kelly as well, haha

On the later PCMs with the 8m/m studs, they used a segment of 10AWG fusible link wire spliced into the alternator output lead.

There's no reason you can't use an actual fuse - and any replacements would be easier to find, and you'll know what it's rated for. Check my website for details; and questions backchannel, please.

6AWG may be a little light for a 200A max rating - I'd have to check (need to update that chart anyhow.) 2AWG is probably an effective minimum, and I use 1AWG for safety's sake.
 
well that sounds simple enough, haha.

checked your site...might be ordering some stuff from there cause i don't have a good "wire hookup" anymore, lol

6awg was just the smallest i went...i ran 2awg for the main alternator to battery and all main grounds to/from the battery.
ran 0awg from the battery to a distribution block in the back for my amps and either 2awg or 4awg from the battery to the distribution pole on the starter relay.
come to think of it....i don't even remember where i used that 6awg, haha...i think it was to one of the amps or the head unit or something...
 
KinesthesiaDrums said:
well that sounds simple enough, haha.

checked your site...might be ordering some stuff from there cause i don't have a good "wire hookup" anymore, lol

6awg was just the smallest i went...i ran 2awg for the main alternator to battery and all main grounds to/from the battery.
ran 0awg from the battery to a distribution block in the back for my amps and either 2awg or 4awg from the battery to the distribution pole on the starter relay.
come to think of it....i don't even remember where i used that 6awg, haha...i think it was to one of the amps or the head unit or something...

I'll be here!

I've added some distribution goodies recently, and bear in mind that I use 1AWG for mains and also offer 4AWG for "distribution" leads - lighting power blocks, amplifiers, and the like. 6AWG is good for amps (most kits come with 8AWG wiring, I've noted,) I just offer 4AWG for secondaries because it's good for a bit more current, and that "buffer" just might be needed...
 
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