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Old 05-18-2013, 07:24 AM   #31
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Originally Posted by BeerChameleon View Post
Bumping old thread can someone tell me what green wire this is? Is it the one that plugs into the alternator that also has a pink wire with it?

This maybe my problem with my alternator not charging fully and dropping to 12volts then back to 14 volts.
what year?

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Old 05-18-2013, 11:36 AM   #32
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what year?
2005

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Old 05-18-2013, 11:50 AM   #33
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No no, if altenator is testing good but having voltage drops like that tells me that the voltage regulator is going out... Here ia the bad news Chrysler put the voltage regulator inside of the ECM so you probably have a bad ecm/computer..

Sorry but go by a Autozone have them test the altenator on the Jeep and see if the regulator passes bet it wont and like I said above that means a new ecm...
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Old 05-18-2013, 05:08 PM   #34
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2005
Mine was the ECU but it never charged, IMO the "coming and going" is more likely ,

(list things I would check)

Battery and its connections
Ground strap at back of engine to frame (diff location on some)
Have alt checked
Use a good set of jumper cables, connect ground of battery to frame of alt (ground only!!) If the prob goes away its ground issue

Then lastly if all above cks good borrow a ECU from any engine that will plug up, (doesn't matter if its a pck up truck or whatever just Chrysler, it will run like crap if its a v8 lol but it will still charge)

Good luck
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Old 05-27-2013, 09:24 PM   #35
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.458 - Have you had a repeat failure?? I'm in a 2000 Sahara Wranger, having the same issue. I am not an electronics expert, but I had access to Mitchell on Demand from a friend. Here's what I've done so far:

1) Check battery - good per O'Reilly Automotive
2) Replaced alternator - No change in performance. I did not take my core in after reading threads so I pulled the new one, reinstalled the old one, and got my $215 + core back. I have the 117 amp alternator (frame ground, 2 wire [green w/orange stripe & "dark green"], 1 big red one)
3) Checked for voltage from "generator field driver" (green/orange stripe) to ground- got 11.81v. If it matters I chose the alternator frame as ground for my cheap multi-meter probe.
4) Back probed (paperclip) "generator field driver on generator field connector terminal 2" (Dark Green wire) - got 338 mV
5) Ohmed the terminals in the alternator - 3 Ohms (lower than the spec of 5 I was given).
6) Ohmed from PCM terminal C (grey plug) pin 25 to both the dark green and green/orange stripe (because I'm not sure which wire from the alternator traces to C25). In both cases I got no response from my meter. It stared at me with a blank mega ohms reading.... so I guess my next step is to tear apart the wiring harness to see if it's broken/shorted?

If I run a jumper wire from whichever wire (drk grn or grn/orange stripe) behind the grey terminal and splice into the corresponding wire in the alternator terminal - Will I damage anything (provided my splices are good). I am thinking if I ran a jumper as a test it would tell me if the wire was actually broken/chaffed/shorting/etc. I envision using something like these: http://www.wiringproducts.com/conten...ick_splice.jpg

My concern is that any of the following are true - my paperclip probes weren't up to snuff, my techniques for troubleshooting weren't as good as possible, my homedepot $40 digital multimeter may not be up to the task (but it seems to work nicely), that I'll end up in the PCM boat with a bunch of others AND possibly have made unnecessary splices.

I'm very interested in anyone's thoughts before I start ripping up the wire looms to determine if I have a short or running a jumper wire.

.458 I'm MOST INTERESTED to determine if you actually troubleshot to root cause of failure (understanding that the assignable cause of failure is, as you mentioned above, a part of the circuit board of the PCM which I'll have to dig up an applied electrical engineer to get fixed).

Thanks guys!!
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Old 05-27-2013, 10:51 PM   #36
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... my home depot $40 digital multimeter may not be up to the task (but it seems to work nicely)
As someone who has worked on electronic circuits since the 60's & have used digital multimeters many times, I'd rather have a basic $10 analog meter with a swinging needle indicator for troubleshooting a Jeep electrical circuit. Analog indicators are easier & faster to interpret which is why modern instrumentation like aircraft cockpits, after a short-lived digital display period, went back to analog displays that are only driven by digital circuitry.
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Old 06-01-2013, 02:24 PM   #37
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::UPDATE::

Dudes! Best news EVER! I decided to day, hope against hope, to check the fusible links this AM. Instead of just propping the hood with the prop-rod, for whatever reason, I propped it against the windshield. This gave me more light, which helped me figure it out.

I ohmed all my minifuses & the fusible links and as expected, they were all fine. Suddenly I noticed a glint of a reflection on the negative wire going to the fuse box. I grabbed the wire just below the black molded plug and the green wire almost fell apart in my hands. Grabbed the wife, had her sit in the cab. Started the Jeep, it showed 12v (battery charge), then I pushed the wire ends together and she started charging!!

Went to O'Reilly and got some 8 gauge wire (1ft), green tape, & heat shrink. Here was my repair process:

1) Cut molded connector off (but in a way it was salvageable for reuse and set aside.
2) Used needle-nosed vice grips to pry the wires from the terminal and bent the terminal back to place in my vice.
3) Cut green wire & disposed of old, stripped 3/4" on green & new black wire. Twisted together, soldered, slipped heat-shrink over the soldered wires and shrunk it with a lighter. Wrapped it with green tape for either myself or the next guy who gets into it.
4) Re-attached to the terminal to the fuse box, re-connected battery, started. Glorious 14v on the voltmeter!!!

My lesson learned: Don't just check the grounds where you think they should be connected. CHECK THE ENTIRE GROUNDING CIRCUIT!!!!!!!

Thanks to you all for the posts and advice. Jerry - you're probably right, I should get a different DVOM. I wasn't very impressed with it's auto-ranging on the ohm job... I should stop being cheap and just get a used Fluke...

I can post pics if requested.
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Old 06-01-2013, 02:33 PM   #38
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Nice job! Finding the cause of electrical problems can be some of the most difficult things to accomplish, they can be maddening!!

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