Alternator Recommendation

[WahooSteeler]

I must have jinxed myself on SCGUY's thread the other day, saying I think I might need to replace my alternator. Get in the MJ today and no start. Jumps immediately, dies as soon as jumper cable is disconnected. 12.7v at the battery terminals per my DMM. Cables were upgraded a while ago, battery has some age but seems ok. 

 

No idea if the one on there is OE (doubt it) or what the amp rating, but know I want to go to a 100/105 amp unit having A/C and power windows/locks.  Looking for just a solid reliable unit, truck still only gets @5k year usage at most. Basically a DD for my college son and a household work vehicle. Basic high powered head unit for stereo, i.e. no external amps (for now LOL). 

 

On Rock Auto they have Pure Energy, Remy, WAI, BBB Industries, and AC Delco Prof available. Any of these can be had delivered for less than $100 and they are new, not reman. They have a Bosch unit for @$110 but its 85 amp and I definitely want 100/105 amp. I searched the tech forum for discussions and most threads were for people looking to get really high amp units and spending $$$. I did see a comment by Eagle on one thread that he'd recommend the Auto Zone Gold 100 amp as it comes with a lifetime warranty. That's great, but if I'm having to get it replaced every 2-3yrs my time is more valuable. Anyhoo, seems like some of the ones available on RockAuto would fit the bill and <$100 is hard to beat for a new unit IMO. The box store units are mostly $150+. Still would like some input from any of you before I make a decision. Thanks!

[eaglescout526]

Delco/Remy is the OEM alt supplier for our Renix engines. I would avoid AutoZone. We kept having a company come in a replace their power steering pump every two months because it was an AutoZone reman and the company was too cheap to go with something good like a Mopar unit. I could look and see what's left of the Mopar alts but I don't think there's much left around.

[WahooSteeler]

6 minutes ago, eaglescout526 said:

Delco/Remy is the OEM alt supplier for our Renix engines. I would avoid AutoZone. We kept having a company come in a replace their power steering pump every two months because it was an AutoZone reman and the company was too cheap to go with something good like a Mopar unit. I could look and see what's left of the Mopar alts but I don't think there's much left around.

 

If there's a Mopar 100 amp unit, I'd be interested. I just looked at RockAuto again and the Remy unit is a Remy Gold, and as mentioned the Delco is a Professional unit. Either one for @$90 shipped. 

[JMO413]

I went with the Delco and am happy with it. I work at a dual line dealership GM/Mopar so I'm s little biased toward Delco. They generally make very good parts. To this day I will only buy AcDelco batteries. Can't beat the performance for the price with AcDelco. IHMO

[eaglescout526]

Honestly, smart money would put money towards any delco part that will fit our Jeeps. Delco makes GM's stuff so you can't go wrong with them when buying aftermarket parts.

 

Nope, no reman or new Mopar 4.0L Renix alts. 

[PIKE]

i agree with what others have said .  After my research this is the one i went with. Still working good.

 

https://www.amazon.com/gp/product/B007QBPT5M/ref=ppx_yo_dt_b_search_asin_image?ie=UTF8&psc=1

 

 

[WahooSteeler]

Thanks guys. I have ordered many AC/Delco parts with confidence knowing they are the major mfr for GM parts and likely well made. That's the direction I'll go......

[Sir Sam]

Is the renix alternator internally voltage regulated or external?

 

for newer Jeeps the ZJ alternator is some like 120 amps. I used a 160 amp alternator from a Durango, but it requires some grinding to clear, whereas the ZJ alternator seems to fit without issue. 
 

However the voltage regulator might give a compatibility issue, you can purchase external voltage regulators. 

[eaglescout526]

Renix/GM alts are regulated internally by the alt. HO regulates it by the ECU.

[ghetdjc320]

2 hours ago, Sir Sam said:

Is the renix alternator internally voltage regulated or external?

 

for newer Jeeps the ZJ alternator is some like 120 amps. I used a 160 amp alternator from a Durango, but it requires some grinding to clear, whereas the ZJ alternator seems to fit without issue. 
 

However the voltage regulator might give a compatibility issue, you can purchase external voltage regulators. 

The ZJ one can be had in the 136a range at max rpm with the stock pulley but swapping on our 4.0 pulley will net a bit more idle amps which is crucial. They are all GM hairpin style alternators and there are large and small case options. I finally went with a Singer 240a alternator which requires the same slight clearancing if the alternator bracket. Used an external adjustable regulator set to 14.2 v and eliminated the ecu regulator. Works great!