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Need electrical help 1998 Caravan #2667309
06/18/19 06:12 PM
06/18/19 06:12 PM
Joined: Nov 2006
Posts: 730
Nampa, ID
MadMatt Offline OP
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Nampa, ID
My 1998 Dodge Grand Caravan Sport with the 3.3 has an electrical issue. It starts and idles fine, but when when the RPM gets above 2300 the battery light comes on and the LCD dash displays go out. I put a voltage meter on the battery, and it shows 13.8-14.2 volts at idle, but when you rev it the voltage jumps as high as 18 volts! The internet says the voltage regulator is in the PCM. Is my only alternative to replace the PCM or could there be another cause? Could it just be a bad alternator. Is there another test I should perform? Any advice is appreciated!


Some see the glass as half empty, some see the glass as half full. I just drink straight out of the bottle.
Re: Need electrical help 1998 Caravan [Re: MadMatt] #2667314
06/18/19 06:22 PM
06/18/19 06:22 PM
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nowhere
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Sniper Offline
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Not likely the alternator. You could pull it and have it tested.

As you heard, the regulator is built into the PCM. However, there is a solution.

Field Replacement Module

Re: Need electrical help 1998 Caravan [Re: Sniper] #2667329
06/18/19 07:07 PM
06/18/19 07:07 PM
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Posts: 20
houston, mo
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johnnmo Offline
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Possibly a ground issue.

Re: Need electrical help 1998 Caravan [Re: johnnmo] #2667374
06/18/19 08:50 PM
06/18/19 08:50 PM
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Posts: 4,267
Morrow, OH
markz528 Online content
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Originally Posted by johnnmo
Possibly a ground issue.


Agree


67 Coronet 500 9.610 @ 139.20 mph
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Re: Need electrical help 1998 Caravan [Re: markz528] #2667379
06/18/19 09:08 PM
06/18/19 09:08 PM
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Posts: 5,193
NEW JERSEY
AARCONV Offline
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Check and clean the wires under the battery.

Re: Need electrical help 1998 Caravan [Re: AARCONV] #2667384
06/18/19 09:27 PM
06/18/19 09:27 PM
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Andrewh Offline
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don't buy that kit. it seems horribly over priced.
you can buy the regulator and plug for under 20 bucks and run the wiring yourself.

Re: Need electrical help 1998 Caravan [Re: markz528] #2667392
06/18/19 09:52 PM
06/18/19 09:52 PM
Joined: Nov 2006
Posts: 730
Nampa, ID
MadMatt Offline OP
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Originally Posted by markz528
Originally Posted by johnnmo
Possibly a ground issue.


Agree


How would a ground issue cause the alternator to overcharge?? What ground would be bad?


Some see the glass as half empty, some see the glass as half full. I just drink straight out of the bottle.
Re: Need electrical help 1998 Caravan [Re: MadMatt] #2667411
06/18/19 11:55 PM
06/18/19 11:55 PM
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Posts: 20
houston, mo
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johnnmo Offline
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Without a ground, the alternator goes to full charge.

Re: Need electrical help 1998 Caravan [Re: johnnmo] #2667419
06/19/19 01:14 AM
06/19/19 01:14 AM
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Balt. Md
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383man Offline
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Originally Posted by johnnmo
Without a ground, the alternator goes to full charge.



Some can and some wont charge at all. I would check the wiring and then unhook the field wire to the PCM to see if it stops charging. On most of them the PCM just ground and ungrounds the field to control output. If it stops charging with the field unhooked then it sounds like the PCM but also make sure the field wire from the alt to the PCM is not grounded as that will make it overcharge. If it still overcharges with the field wire at the alt unhooked then it sounds like an internal alt problem. A grounded brush could also keep it overcharging. And as was said you can wire in an external regulator as I have done that for a few people who did not want to buy and alt. You just run the field ground wire to the ext regulator and also wire 12 volts at key on to the ext regulator to do it that way if its in the PCM. Ron

Re: Need electrical help 1998 Caravan [Re: MadMatt] #2667699
06/19/19 07:32 PM
06/19/19 07:32 PM
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USA
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Originally Posted by MadMatt
My 1998 Dodge Grand Caravan Sport with the 3.3 has an electrical issue. It starts and idles fine, but when when the RPM gets above 2300 the battery light comes on and the LCD dash displays go out. Any advice is appreciated!


My fuzzy memory seems to recall those year minivans have a cold solder joint in a ground wire to the instrument panel that is a common problem.

Re: Need electrical help 1998 Caravan [Re: 360view] #2667701
06/19/19 07:32 PM
06/19/19 07:32 PM
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Posts: 8,162
USA
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Re: Need electrical help 1998 Caravan [Re: 360view] #2667702
06/19/19 07:36 PM
06/19/19 07:36 PM
Joined: Jan 2006
Posts: 8,162
USA
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Marked in red

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Re: Need electrical help 1998 Caravan [Re: 360view] #2667883
06/20/19 09:46 AM
06/20/19 09:46 AM
Joined: Sep 2003
Posts: 19,241
north of coder
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don't forget to check the wiring harness [everything !] by the battery tray. battery outgassing over the years will attack the insulation, and cause an untold amount of hair pulling, until you find the culprit. [especially the harness parts that are hidden.]
if you have those CLAMP-ON replacement battery terminals, GET RID OF THEM ! those cause MORE problems than you can count !
REPLACE the cables BEFORE you begin to even TRY diagnosing the problem ! mad
beer







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