• NAXJA is having its 18th annual March Membership Drive!!!
    Everyone who joins or renews during March will be entered into a drawing!
    More Information - Join/Renew
  • Welcome to the new NAXJA Forum! If your password does not work, please use "Forgot your password?" link on the log-in page. Please feel free to reach out to [email protected] if we can provide any assistance.

Upgrading an alternator?

Double Down

NAXJA Forum User
Location
Cincinnati, Ohio
I was thinking and I noticed that during the same years 96-97 and up, Cherokee had a higher current alternator they used for some of the Jeeps (117, 124 vs 90 amp). If you are looking to upgrade to a higher current alternator, can you swap higher current stock one for a stock 90 amp? If so, is there anything you have to worry about?

Thanks,

Double Down
 
Jeep has changed the alternator type a couple of times, but as long as you stay within the range of years that uses the same type as your XJ, you can just take yours out and bolt in the higher output alternator with no other changes and no problems other than paying for the new one.
 
if you want more power for less you can also upgrade to a 136 amp alt. from a v8 grand cherokee. however it requires you do minimal grinding to the cast bracket. i think the best part of all is the lifetime warrinty and it only cost me 50 to upgrade at the parts store.
 
Will it fit an 88 ?

Do you have a part #?

my alternator is about to die and I am looking for a cheap upgrade.


TIA
 
Cesar said:
Will it fit an 88 ?

Do you have a part #?

my alternator is about to die and I am looking for a cheap upgrade.


TIA

In 91 they changed from the GM style to the Nipendenso. The GM (pre 91) is internally regulated and the Nipendenso is not. The GM can be upgraded to 140 but the newer nipendensos can be swapped for a bigger unit froma grand or ?
 
Anyone have any idea what size wire you should upgrade to when upgrading just the alternator? It looks like the stock wire is a 6gauge? on 97 Cherokee, so is it safe to go up a 4 or 2 gauge when upgrading from a 90 amp to a 136 amp alt?

thanks,

Chris (Double Down)
 
How big can you afford?

How big will physically fit?

These are the only things to concern yourself with. As the guy said-- bigger cable is NEVER a problem.

I always retrofit 2AWG wedling cable into the electrical system <alternator charge lead, grounds in the engine compartment, start lead, etc> of any vehicle I buy, and have very few electrical problems- none of which are caused by anything other than a finite lifespan of electrical components.
 
Burntkat,

Call me stupid, but I was wondering if you have any pics of the setups with the 2awg cables? I would like to do the same but don't really know what I should do or start with. What exactly should I change/upgrad in regards to cables? How do you recommend doing it (remember, I'm not an electrical genius) ;)

Beebe (Double Down)
 
Doubledown:
OK, you're stupid.. <joking, dude>

This sounds like a good excuse for a tech article.

I'll write one up, but if you have any specific questions other than the following, ask away:

cables we're concerned with:
Ground-
-battery to engine block
-battery to body
-body to engine block <yes I know it's electrically duplicated-- not a bad thing, though.>

Positive-
-battery to isolator
-battery to alternator <on my 90 w/ GM alternator, this is the one that has a ring terminal on the alternator end and bolts to the large lug on the case>- this is the charge lead.. and if you use an isolator in a dual battery setup, this will be moved to the "A" terminal of the isolator.
-battery to starter <the less resistance, and hence more voltage, here the better>

All the other wires on the alternator are used for field excitation and the like, and thus not really in need of upgrading <they don't carry high current>.

I use 2AWG welding cable, cuz it's cheaper than that grabasstic Monster Cable, and if it'll handle welding spall dripping on it, it'll handle underhood heat. Don't pay more than $1/foot.

Additionally- if using a dual battery setup with the Ford starter solenoid for auto-slave like I recently posted, you'll need various 2AWG jumpers-

jumpers-
battery1 to isolator
battery2 to isolator
battery1 to term1 of solenoid
battery2 to term2 of solenoid

To make these leads <all of them>, I use a razor knife, a propane torch <tuned down to a pencil-tip flame>, 2AWG ring terminals <I use the less expensive gold-plated terminals from the car stereo shop- $1 each- and they don't oxidize due to the gold coating>, silver solder <from radio shack>, and HIGH QUALITY heat shrink tubing <not the stiff stuff, the very flexible- I believe the one you want is NOT the polybutylene stuff, but it's been a while since I bought any..

Measure cables to your component locations and cut with a set of cable cutters <preferably- $7 at Radio Shack and worth it> or a hacksaw <messy cut>.

Strip 3/4" of insulation and put the terminal over the bare wire. Light torch and heat the END of the terminal <convection will carry the heat to the wire, and this avoids burning the jacket of the cable>.

Feed solder to the wire's stripped end and flow it until the entire surface of the stripped end is coated in a shiny layer of solder <NO Gobs!>. "Solder for inspectability" as they tell us in the DoD.

let cool <ask me how I know-- momentary lapse of reason!

cut a sleeve of heat shrink long enough to cover the barrel of the terminal and 1" onto the cable. Using a heat gun or your stove top set to high, shrink the sleeve down to the cable.

Install!

If you have a high outut soldering gun, it's even better to use- but most folks don't have one sufficient to solder on 2 AWG.

While you're at this, it might be a good idea to run a piece of 4AWG <or better, if you're running a serious sound system> to the back of the vehicle so you can put in a 12V cigarette lighter plug and disconnect. Unless you're a basshead, this should be more current than you'll EVER need. Remember to fuse this lead in the engine compartment within 18" of the battery, and use a rubber grommet in the firewall where you penetrate <wouldn't be bad to seal over it with RTV, too, since we're Jeepers>.

Suggest putting a fuse on the leads going to the batteries from the isolator, if you're going that route. One in series on the autoslave cables, too.

Any questions?


Double Down said:
Burntkat,

Call me stupid, but I was wondering if you have any pics of the setups with the 2awg cables? I would like to do the same but don't really know what I should do or start with. What exactly should I change/upgrad in regards to cables? How do you recommend doing it (remember, I'm not an electrical genius) ;)

Beebe (Double Down)
 
Yeah, when can you come over LOL

Guess it's project time this weekend, sweet.

I'll read this over more when I can see my Jeep inside to see what you are talking about...I'm more of a visual person so I will take a look at stuff and get back to you.

Thanks for all the help,

Beebe
 
it's real simple guys-- nothing to it.

shoot me a PM if you need more info

best part- if you wire in the autoslave feature, and kill the main battery-- a jumpstart off the second battery is the flip of a switch away.
 
Just a heads up for 91 or newer XJ owners. The posting at http://www.pirate4x4.com/forum/show...threadid=172316
is really well done but is not an exact fit for the standard 90 amp alternator. As one guy said you will need to do a little grinding on the alternator bracket, but it is minor. The bottom bolt holes will not line up. THey are off by about 1/2 of an inch. I actually left the bottom bolt out since it is in there really good and there is no play whatsoever. Just a heads up to all those going the 136 amp route. Cheers
 
Are you sure that you got the right alternator? I got a 136 amp for a ZJ from Autozone and the only thing that I did was change the pulley. Went in just like it was made for my XJ.

Robert
 
Back
Top