Alternator Wiring - 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 Wrangler Forums > YJ Wrangler Technical Forum > Alternator Wiring

Poison spyder items @ oconee off road 706 534 9955Oconee Offroad Sales Tech are Available To Help!Zone Offroad Body and Suspension Lift Kits, Brackets, Disc

Reply
Unread 08-20-2009, 02:57 PM   #1
demesauce
Registered User
1988 YJ Wrangler 
 
Join Date: Nov 2008
Location: Fresno, CA
Posts: 9
Alternator Wiring

Hi there, been trying to re-wire my jeep for a while now. Almost all done but I am stuck on the alternator. My jeep is an 1988 YJ with the 4.2, but I recently did the MPI conversion. Everything went pretty well, just time consuming. The jeep starts and runs, but the old alternator is still in place. It seems to be charging, but keeps kicking the check engine light on. I bought the 92-95 style alternator, but need some assistance on how to wire the thing. Any help would be appreciated. I read somewhere about the Dealership part # 56017763, but I'd rather now spend the $135. Thanks a lot

Phil

demesauce is offline   Reply With Quote Quick reply to this message
Unread 08-20-2009, 06:42 PM   #2
Alfons
Registered User
1992 YJ Wrangler 
 
Join Date: Jul 2005
Location: Ontario, Canada
Posts: 2,218
Quote:
Originally Posted by demesauce View Post
Hi there, been trying to re-wire my jeep for a while now. Almost all done but I am stuck on the alternator. My jeep is an 1988 YJ with the 4.2, but I recently did the MPI conversion. Everything went pretty well, just time consuming. The jeep starts and runs, but the old alternator is still in place. It seems to be charging, but keeps kicking the check engine light on. I bought the 92-95 style alternator, but need some assistance on how to wire the thing. Any help would be appreciated. I read somewhere about the Dealership part # 56017763, but I'd rather now spend the $135. Thanks a lot

Phil
First you might want to check on what the stored diagnostic codes are that cause you to get a check-engine-light.

I'm assuming that you have installed the 4.0 engine bay harness if you went through an "mpi conversion", and if so, all the wiring/connectors are there to correctly attach a "new style" alternator - this alternator needs the ECU to regulate the charging voltage.

What's the dealership part you mention in your post?
Alfons is offline   Reply With Quote Quick reply to this message
Unread 08-20-2009, 07:51 PM   #3
demesauce
Registered User
1988 YJ Wrangler 
 
Join Date: Nov 2008
Location: Fresno, CA
Posts: 9
All of the error codes refer to the alternator. I have the ECM/wiring harness from the 4.0 jeep. And the error code is saying that the alternator is not talking to the ECM. The problem is the wiring harness is from the 4.0 but the alternator is from the 4.2. I need help wiring up my new 4.0 alternator to the rest of my 4.0 system.
demesauce is offline   Reply With Quote Quick reply to this message
Unread 08-20-2009, 08:16 PM   #4
Gobi_Gred
Registered User
1987 YJ Wrangler 
 
Join Date: Sep 2008
Location: Omaha Neblastya
Posts: 277
I just went through this yesterday. If you have a 4.2 alt. then you should need to install a 7.5 amp diode on the feild wire from your new harness. If you have a 4.0 alt. then there should be 2 green wires on the back of it. One should have a black stripe. Im a little foggy on which one is which but one of them hooks to the alt. feild wire from your new harness the other gets hooked to a switched 12v source. The feild wire in my Hesco harness is blue.
Gobi_Gred is offline   Reply With Quote Quick reply to this message
Reply

Quick Reply
Message:
Options

Register Now

In order to be able to post messages on the JeepForum.com forums, you must first register.
Please enter your desired user name, your email address and other required details in the form below.
User Name:
Password
Please enter a password for your user account. Note that passwords are case-sensitive.
Password:
Confirm Password:
Email Address
Please enter a valid e-mail address for yourself.
Note: All free e-mails have been banned due to mis-use. (Yahoo, Gmail, Hotmail, etc.)
Don't have a non-free e-mail address? Click here for a solution: Manual Account Creation
Email Address:

Log-in

Human Verification

In order to verify that you are a human and not a spam bot, please enter the answer into the following box below based on the instructions contained in the graphic.


Thread Tools


Suggested Threads





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.