Alternator Problems-3 Bad Ones in a Row?!?

muddyyj95 · 08-15-2009, 02:56 AM

I had the bearing on the original alternator finally bite the dust. So I swapped it out for an Autozone reman. Mistake? The new one registered halfway between 9 & 14 on the guage. I took it off & took it back & they tested it three times & said it was good. Back home, put it back on. Drive Jeep, Jeep Dies. Charge battery back up & Drive to Autozone. They test it on the Jeep & say it's bad. Got second new alternator, take home & put it on. Still halfway between 9 & 14. Drive Jeep to different Autozone. Test it on Jeep, low voltage. Drive home. Now I'm a pro at taking this alternator on and off Jeep & can do it in less than ten minutes. Off comes the alternator- good thing I have crappy Aveo to drive- drive back to autozone- test fails. Take new alternator home (after they test it- ok), Install. Same thing. Comes up about 11.00 (amps?) on tester. Crap, Three bad ones in a row from two different Autozones? I think not? My buddy brings over Bosch reman. alternator he bought for his 98 Cherokee. Looks like the same one. The sticker on the Bosch says Externally regulated. I thought mine was internally regulated. Don't want to put it on unless I'm sure it's the same...If it's the same I'll try & swap it out tomorrow.

Is my alternator externally regulated? Autozone Part #13199

What else could I check on the Jeep? The battery terminals are clean.

Is there anything in the Jeeps arsenal to kill an alternator & make it fail the test when I bring it back there? Do Jeeps have that much power?

95 Wrangler 4.0 six 5 sp

**dodger889** · 08-15-2009, 05:45 AM

Alternator is control by the ECM . Check your connection with the two small wires . One should have battery voltage when you turn on the key. The other one should have power when in the charge mode with. What happen to mine was one of the wires was broken right at the connector it's self.

chondamx · 08-15-2009, 08:42 AM

Check the small wires dodger mentioned along with all of your grounds, although i suspect you would have noticed a problem with them having taking the alt off so many times. Also double check that your battery cables arent only clean but tight as well.

DriveTooMuch · 08-15-2009, 10:14 AM

Is my alternator externally regulated? Autozone Part #13199

^ That is the question ^

DriveTooMuch · 08-15-2009, 10:22 AM

You can see how some are regulated by the computer apparently. There is reference here in this thread though it is a 94 cherokee, especially second post down. http://www.jeepsunlimited.com/forums/showthread.php?p=4427840

**sentinal02** · 08-15-2009, 10:36 AM

Quote:

Originally Posted by muddyyj95

Is my alternator externally regulated? Autozone Part #13199

yes it is. controlled via the ecu. also check the two 50 amp fuses in the PDC. if they blow then the alt can put out power but it will never reach the rest of the electrical system.

JeepsOLot · 08-15-2009, 10:44 AM

My friend had the exact same issues you did with Autozone alternators! This was on his '86 Monte Carlo. He got the lifetime warranty, but, if you have to keep changing them, what's the point!? He just went to Advance, and never had a problem again. Try going to another source for the alternator, see if that helps.

Jerry

DriveTooMuch · 08-15-2009, 10:53 AM

I like Autozone, I just do not do rebuilt electrical anything with them. Too many problems with the starters as well, the rebuilt stuff. But not sure about this problem though, it may be more than just the alternator itself. I have a 95 and I just may have to deal with this myself someday.

ziebartrob · 08-15-2009, 11:04 AM

Man I had the EXACT same issue w/ my 91. Got 3 diff alt from Auto Zone. Turns out it was a Maxi fuse that was blown in the power dist box under the hood. Def check that if you havent already.

Sorry, didnt realize that is 'bout exactly what Sentinal said, mine was a 50A maxi fuse.

DriveTooMuch · 08-15-2009, 11:06 AM

Pardon my ignorance but what, and where is the maxi fuse? Is that the box near the battery?

ziebartrob · 08-15-2009, 11:11 AM

Yes the power dist box is under hood on pass side. A maxi fuse is simply a BIG two prong spade fuse, think the 50A are red if I rember correctly.

muddyyj95 · 08-15-2009, 10:03 PM

Thanks guys. My jeeps recently rejected the valve cover (new oil leak) so I cleaned the negative ground on the engine block, but that didn't make a difference.

I'll check those fuses tomorrow.

muddyyj95 · 08-17-2009, 10:27 PM

It was the fuses. Thanks again.

DriveTooMuch · 08-17-2009, 10:56 PM

It did! Cool! Wow that is good news and something I will keep in mind if that happens to me.

**dodger889** · 08-18-2009, 06:21 AM

Hey the next time you change the alternator disconnect the battery it will save you time.

08-15-2009, 10:03 PM	#12
muddyyj95 Registered User Join Date: Aug 2007 Location: Crest Hill, Il Posts: 14 Profile Gallery Classifieds My Jeeps	Thanks guys. My jeeps recently rejected the valve cover (new oil leak) so I cleaned the negative ground on the engine block, but that didn't make a difference. I'll check those fuses tomorrow. __________________ Jeep Joe 95 YJ 83 CJ7 60 CJ3B 96 Grand Cherokee- RIP GroceryGetter 02 Liberty

08-17-2009, 10:27 PM	#13
muddyyj95 Registered User Join Date: Aug 2007 Location: Crest Hill, Il Posts: 14 Profile Gallery Classifieds My Jeeps	It was the fuses. Thanks again. __________________ Jeep Joe 95 YJ 83 CJ7 60 CJ3B 96 Grand Cherokee- RIP GroceryGetter 02 Liberty