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2003 Town & Country:Charging Problem


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WillG
Novice

Jun 22, 2010, 9:04 AM

Post #1 of 10 (5080 views)
2003 Town & Country:Charging Problem Sign In

2003
Chrysler
Town &Country LXi
3.8L
169,872 mi.

The Problem:
The alternator will not charge the battery. I removed both the alternator (OEM) and battery (3yr. old) and had them tested off the car at the auto parts chain store where the battery was purchased. They both tested OK. The only fault code stored is P1684 (Batt. Disc.). The only wiring diagrams I have are in the Chilton's Repair Manual. They do not show any fuses or relays in the charging circuit. I suspect the Powertrain Control Module (PCM) but I can't rule out anything without testing the circuit continuity.

My Questions:
1. Can the PCM be tested off of the vehicle?
2. Does anyone
have a copy of the OEM wiring diagram that they will share with me?
3. What else should I check?

Thanks for any help.





Hammer Time
Ultimate Carjunky / Moderator
Hammer Time profile image

Jun 22, 2010, 9:28 AM

Post #2 of 10 (5065 views)
Re: 2003 Town & Country:Charging Problem Sign In

Test for power at the main terminal of the alternator with the key off. If you have no power, then the fuse between the alternator output and the battery is blown.



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We offer help in answering questions, clarifying things or giving advice but we are not a substitute for an on-site inspection by a professional.



WillG
Novice

Jun 22, 2010, 10:31 AM

Post #3 of 10 (5061 views)
Re: 2003 Town & Country:Charging Problem Sign In

Thanks for the reply!

I forgot to mention that I already did that. Continuity to the battery is OK.

I really need a correct schematic with the pin-outs for the PCM connectors.


Hammer Time
Ultimate Carjunky / Moderator
Hammer Time profile image

Jun 22, 2010, 10:42 AM

Post #4 of 10 (5059 views)
Re: 2003 Town & Country:Charging Problem Sign In

Here ya go







~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~

We offer help in answering questions, clarifying things or giving advice but we are not a substitute for an on-site inspection by a professional.



WillG
Novice

Jun 22, 2010, 11:10 AM

Post #5 of 10 (5056 views)
Re: 2003 Town & Country:Charging Problem Sign In

THANKS AGAIN! I'll blow the images up in Paintshop for a better view.
Do you know if the PCM can be tested OFF of the car?

Now I've got to get to work again.


Hammer Time
Ultimate Carjunky / Moderator
Hammer Time profile image

Jun 22, 2010, 11:32 AM

Post #6 of 10 (5054 views)
Re: 2003 Town & Country:Charging Problem Sign In

There is no way to positively test a PCM either off the car or on the car.

You can try full fielding the alternator and if it charges then you can install an external regulator to solve the problem.



~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~

We offer help in answering questions, clarifying things or giving advice but we are not a substitute for an on-site inspection by a professional.



WillG
Novice

Jun 22, 2010, 2:44 PM

Post #7 of 10 (5048 views)
Re: 2003 Town & Country:Charging Problem Sign In

MORE HELP PLEASE:

I tried the full field test on the alternator using a spare alternator connector pigtail. The Voltage at the Alt. started climbing from 12+ to over 17 VDC in a couple of seconds before I removed the full batt. voltage from the GFC. I suppose that means the Alt. is OK, right?

I did a continuity test from the alt. gen. field conn. to pin # 8 of the PCM C1 (SBEC)as shown in your table for the Generator Field Control. I expected either no resistance, a short or a ground; but instead, I measured 9.7-9.9 ohm resistance. I don't have the factory schematic, but Hayne's shows a straight connection. Is there something else in the circuit between the PCM and alt. GFC conn.?

The ground side of the alt. conn. is less than 1 ohm to ground, and I found no short between the GFC side of the conn. and ground.

If I do bypass the wiring harness, can you recommend an external regulator?


Hammer Time
Ultimate Carjunky / Moderator
Hammer Time profile image

Jun 22, 2010, 3:03 PM

Post #8 of 10 (5045 views)
Re: 2003 Town & Country:Charging Problem Sign In

That doesn't sound like enough to be a problem. If your in doubt, try patching in an overlay wire from the PCM directly to the alternator connection. It sounds like you on the right track though.



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We offer help in answering questions, clarifying things or giving advice but we are not a substitute for an on-site inspection by a professional.



Sidom
Veteran / Moderator
Sidom profile image

Jun 22, 2010, 8:41 PM

Post #9 of 10 (5037 views)
Re: 2003 Town & Country:Charging Problem Sign In

Those wire need to be traced down to be sure they aren't the problem.

I haven't installed an external on that model of Chry, I know an external will work on the older PCMs. If you went that route I would moniter the charging voltage very carefully for a while, under all conditions.

For the older PCMs you just used an old Chry external voltage regulator, pigtail, 12v source on the top pin and then the 2 alt wire to the pins (the alt wires don't matter which pins they go to, I always keep the supply with the 12v source) and the body needed to be ground as well.









Another option would be an alt with an internal voltage regulator but that would require new brackets, belts, and be a lot of work.




Oops.......Replied to HT instead of Will.........You guys know what I meant......been along day Crazy


(This post was edited by Sidom on Jun 22, 2010, 8:43 PM)


WillG
Novice

Jun 23, 2010, 12:48 PM

Post #10 of 10 (5026 views)
Re: 2003 Town & Country:Charging Problem Sign In

Thanks guys! I'm still trying to find the source of the resistance in the GFC wire between the PCM and the alt. conn. The schematic agrees with the H. Manual and doesn't show anything there. Still looking. I just didn't want to bypass some other black box and kill the alt.






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