Alternator Question - JeepForum.com
Search  
Sign Up   Today's Posts
User: Pass: Remember?
Advertise Here
Jeep Home Jeep Forum Jeep Classifieds Jeep Registry JeepSpace Jeep Reviews Jeep Gallery Jeep Clubs Jeep Groups Jeep Videos Jeep Events Jeep Articles
Go Back JeepForum.com > Models > Jeep CJ Forum > Alternator Question

Introducing MONSTALINER™ UV Permanent DIY Roll On Bed LineFS: 2007-2013 Jeep Wrangler "HALO" Angel Eye KitFS: Wranger BRIGHT License Plate LED! Just $3! Great value

Reply
Unread 05-25-2013, 10:40 AM   #1
CJ7Danomite
Registered User
 
Join Date: Jan 2013
Location: Stafford, TX
Posts: 5
Alternator Question

Hi everyone,

So a little back story before I get to my questions. I was driving the jeep last night and stopped for gas. When I tried to get going again it wouldn't turn over. I was able to bump start it (by myself, in an HEB parking lot...) and get it back home, but it wasn't able to start from the battery anymore. I figured it was the battery, so I went to autozone and picked up a new one. When I got that it, the voltage meter was only saying it was at about 11-12 volts when I was driving, so when I returned the core battery they check my alternator and they said that it was only putting out about 12v, when it should really be putting out about 13-14v. They recommended I replace the alternator too.

I unfortunately am just getting started in the world of do-it-yourself repairs, and I was wondering if anyone could weigh in on whether that would be the right approach, or if there is anything else I should check before I just start throwing money at it and replacing entire components.

Thanks,
Dan

BTW: It's an 84 CJ7 inline 6 4.2

CJ7Danomite is offline   Reply With Quote
Unread 05-25-2013, 11:26 AM   #2
scoutboater
Registered User
1974 CJ5 
 
Join Date: Oct 2011
Location: Scottsboro, Alabama
Posts: 311
They are correct, your alternator should put out between 13 and 14v when the engine is running. Also, your alternator is internally regulated, meaning there is no other little part that could be causing the problems. That being said, if you really want to be sure, you can take a volt meter to the hot post on the back of the alternator while the engine is running and confirm that there is only 12v there. If this is the case, you need a new alternator.

If, for some incredibly weird reason, you have 13-14v at the alternator, you need to start chasing wires and look for a broken wire or a bad connection.

Also, be forwarned that if you get an arm/sleeve/ponytail/anything caught up in the fan or the belt while the engine is running, you are going in there with it. Just watch your fingers and stay away from moving parts.
scoutboater is offline   Reply With Quote
Unread 05-25-2013, 12:56 PM   #3
CJ7Danomite
Registered User
 
Join Date: Jan 2013
Location: Stafford, TX
Posts: 5
Thanks for the reply. I went ahead and just took the whole alternator in to Autozone and got a new one. They hooked my old one up the machine and it started making a god awful sound. When he came back he told me my alternator started coming apart while he was testing it. So it failed.

Thanks for the tip. I have everything unhooked as of now, but I will definitely keep all my parts out of the way!

-Dan
CJ7Danomite is offline   Reply With Quote
Unread 05-26-2013, 12:36 PM   #4
motiv8ya
Registered User
1979 CJ7 
 
Join Date: Dec 2008
Location: Las Vegas, Nevada
Posts: 889
It's worth the extra 10 minutes to make up a new set of wires for the alternator. You can get the new 'GM' pigtail for the alternator at any parts store (on the shelf near the fuses) and go from there. Just a little insurance. I just did mine when I upgraded my alternator because the old wiring was burnt.
__________________
Fueled by the Fallen: http://www.fueledbythefallen.org
Heroes Helping Humanity: http://heroeshelpinghumanity.org/home/
WarMachines702: http://warmachines702.com/
motiv8ya is offline   Reply With Quote




Jeep, Wrangler, Cherokee, Grand Cherokee, and other models are copyrighted and trademarked to Jeep/Chrysler Corporation. JeepForum.com is not in any way associated with Jeep or the Chrysler Corp.