bigboy813

Hello I am currently still searching for a resolution for my recent voltage drop after my new alternator replacement and am looking for a 2000 or 2001 Xj owner with a similar issue. The problem started when replacing my alternator with an Ultima from Oreilly even though it tested good in store I still find it suspect, but I dont think they will replace it. I have got some advice like changing my gounds and such which I have, I even went a step further to cleaning the grounds and buying brand new engine block ground nuts. The only ground left is the rear engine to fire wall ground which has not been change and is covered in oil but that was not an issue before hand so I dont see it as asuspect to give me a positive result unless i am wrong.

Some things I have personally done with no solutions
-Got my battery check it good cuase its brand new .
-Got my alternator check at orielly it tested good which i think is bs.
-New estimated 4~6 guage grounds
-New terminals and 1 new power wire from the alternator.

People may say it is because of my stereo or what not but I definitely know its not. Reason being I have the option to turn my headunit off which in turn shuts my amps of because the lights on both amps shut off which means they have totally shutdown.

Lastly when my vehicle is running with my headlights on only voltage drops to around 13.3v~13.5v, also with A/C or heater it will drop to around 13 and go a tad below which is bs with a new alternator and battery both less than 5 months old.

Sorry is this is difficult to read it is early in the day and im pretty tired.
Hmmm again sorry this is pretty much border lined Advanced/Oem Tech.

Zj heep

I would think that is good if you did a factory replacement? My jeep will run around 12.5 to 13 at idle with headlights and electric fan running but driving down the road will run 13.5 to 14 . Good luck.

bigboy813

Only reason it bothers me is with the OE alternator i never had voltage drops no matter what

Illuminator

The ventilation system pulls alot so a good sized drop is to be expected. Was the replacement alternator a upgrade, and how many amps was the factory? Perhaps your's had a high output factory alternator and the replacement is not.

bigboy813

Direct replacement 117amps like the stock one for 2000 xj's

BotakBeng

My 2000 came with 124 Amp Alternator (info from Chrysler Group LLC Customer Assistance)....you might want to double check yours.

GL

bigboy813

Do you have a part number or picture to see what it looks like ?

BotakBeng

You got me confused now.
My build sheet from Chrysler says i have BASS 124 Amp Alternator but when i look up 2000 parts Catalog, i get part# 56041 822AA which is 117 Amp

I would call the stealership with your VIN and find out which alternator part# you required.

Sorry i can't be of any help.


GL.

LegalizeFreedom

Still having issues? I think that engine ground is suspect. You got to understand this is the main place the alternator grounds to. Its "the big 3". Wish i knew this back in high school when putting a 0 gauge wire from a amp straight to the battery and was losing sooo much.

Your only strong as your weakest link, believe me i know, with 18 inch arms and carpal tunnel. The big 3 is what makes your main power source one solid strong source. Upgrade these three wires.

>The battery to body ground
>The battery to alternator positive
and last but not least...
>The engine ground

You see thats the main way your alternator is connected to the negative/ground. On top of that i always run a separate wire from the negative battery post to one of the alternators mounting bolts. Sorry so lengthy.

kusman

Not all alternators are made equal. I had the same issue on my other vehicle where I replaced the alternator which had a 73A rating, yet realistically, it was delivering maybe only 45A. I know because you can count amperage on the lights and fan and then see the voltage drops.
And if you are seeing 12.5V then it means you are discharging the battery. Normally, the voltage should not fall below 13V.

I think you should take it to the shop and ask them to test in under load - put some fans, lights, whatever on it and then measure the voltage.

LegalizeFreedom

True test it again. The amp rating on alternators is its peak at like 2000rpms or so. Bad grounds can create voltage drops for sure.

bigboy813

Maybe I will have them test it with all the auxiliary crap on but yeah i need that rear motor ground. I will probably upgrade it to a 4 ground guage strap from summit.

2001XJWeekender

Replaced the alt in my 2001 with an autozone reman rated @117amps. I later converted from a clutch fan to an efan.

With the lights, a/c, fogs1&2, radio, ipod in outlet 1, and a gps in the 2nd outlet, both fans blowing, sitting in park at 700 rpm idle, my voltage sits at around 12.3V. As soon as I get the rpms to 1000+, my voltage gets into 13-13.4 volts.

So far I haven't killed my battery or alternator with this setup.



K