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Upgrading the Alternator

wilson0309

NAXJA Forum User
I have added some offroad lights to my roof rack on my cherokee. I have 4 facing front and 2 rear. So I was going to upgrade my alternator and battery to account for the load being placed on them. I called AutoZone and they are saying that stock amprege is 100amp. They don't have an upgrade. Is a 100amp suffcient for what I am doing or will I need to track down a better alternator? Also Where can I find one if need be!
 
Here is a thread with responses when I had a similar question:
http://www.naxja.org/forum/showthread.php?s=&threadid=8537

I chose to put in a larger cs144 alternator in place of the cs130. It puts out 140 amps. I got it from www.alternatorparts.com. I had to grind alot on the frame to fit it including removing one of the welded on nuts to mount the front skid and modify the rear mounting bracket. It works well but, If I had it to do over, I would probably just upgrade the wiring and find a good lifetime warranty replacement.
 
I have the factory HD alternator (130 Amps) and an Exide Orbital Deep Cycle battery (like Optima deep cycle). I run a Warn M8000 winch, 2 electric fans (10 amps each), and 100 Watt Hella lights (8.5 amps) and have no electrical problems. The battery is the key - it'll run 50 amp/hours x 20 hours, so it always has plenty of juice. It costs about $179 though.
 
There are plenty upgrades out here as far as peak amps, but finding one that has high amps (100) at Idle leaves you with Mean Green...some serious $$
 
In 1990 Jeep used three different alternators in the XJ, and 100 amps was the top of the line -- used only in Laredos, Limiteds, and those with the heavy duty electrical option. Auto Zone should know this, since their own catalog lists the lower output models. Their rebuilts are available in 63 and 80 amp, I believe. Their "new" alternator is 100 amps -- unless it's not. Even for their new one with lifetime warranty, quality control is spotty. I bought one for an '88 MJ. First try was DOA, which I didn't find out until after I had installed it. I made them bench test the replacement before I left the store, and it tested 100 amps. However, at idle my headlights flicker and I can see the voltmeter needle wobbling -- and I don't have any high amp accessories running.

I'd suggest Mr. Alternator, or a Mean Green.
 
I just upgraded mine last weekend. Go to truckperformance.com. They have a 140 amp Powermaster, 90 amps at idle. Direct replacement of OEM. $149 without any core charge. About the same as MeanGreen less then half the $. Nice unit too!
 
awesome
thats what I will do. I will get a deep cycle optima battery and also get that alternator. that should curve any light issue that i should have.
 
the powermaster I got the first time was a bad unit. The bearing went bad and the thing would peg the needle in the right at a light with the headlights and radio on. I sent it back to them. I haven't had a problem. Mean Greens are really nice, but the price is twice as much. So I figure for haven't to send one back to Powermaster and the down time, I was still ahead of the game. I do have a Optima Red Top and HD battery cables from Jeepers Creepers. Everything works great. Juice
 
Got any pics of that auxiliary set up? I have been looking into doing it for sometime. I have the battery tray to do it just wanted to see it done. Thanks Juice
 
I mounted the Yellow Top in the rear, just behind the right rear wheel well and the tail gate. Used a battery box and tied it down through the floor board. Also added an auxiliary fuse center inside the battery box. I'll run a power inverter, a small 12 volt cooler and misc. lights/excessories through that fuse center. Ran a #4 wire up to the front for the tie in. The Optima's gas very little, if any, as they charge so you don't have to worry about inside installs.
 
wow that post on pirates is awesome.

I am deffinatly going to do that!

I am all about saving the cash
:D :D :D :D :D :D :D
 
wilson0309 said:
wow that post on pirates is awesome.

I am deffinatly going to do that!

I am all about saving the cash
:D :D :D :D :D :D :D

Well, I suggest you go back and read the fine print. You have a '90 -- I believe the article stated that the Denso alternator was used beginning in 1991. I think you have a GM/Delco alternator, the same as the rest of us with Renix-era XJs and MJs.
 
The Delco unit can be upgraded, find a local shop to do it for you. I have a local here in San Jose that does a good job, my Delco is now giving me about 180A a peak (but I got lucky and got a good rotor setup.) Rod can do 140A or so pretty consistently, and still give some charge at idle.

I don't usually plan on high power usage at idle, or for extended periods - until I get around to adding the two deep cycle batteries I have in mind... Generally, if you plan on a lot of power usage when sitting still you may want to add an auxiliary throttle control so you can run the engine up to around 2000rpm when you need to use a lot of electricity. No sense straining your battery unnecessarily...

5-90
 
I agree with 5-90...a GOOD local shop can handle it...A 12SI delco with the correct rotor and a good stator will work very well. The one I built is good for 145 amps...don't forget to upgrade the wiring from alternator to powerpoint attachment.
 
Again remember, the lower the paek output in the RPM range, the better. If I could find a setup with 100amps near idle besides Mean Green I'd be all over it. Our Battery cables are 0/ welding.

Also running the headlights off of relays.
 
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