charging system light

[cris]

hi my charging system light came on a week ago on my 2002 3.7 sport, yesterday the battery died so got a new one, driving around today it came on again, do you think its the alternator, i looked all the connections and all looks good, thanks

 

[CobraNutt]

Yes...most likely alternator and/or bad ground. Did you test the battery before you replaced it?

Sent from my mystical handheld gizmo.

 

[cris]

when i looked at the battery it looked corroded on the terminals and on the tray area so i thought it needed replacing so i didnt test it where is the ground,

 

[LiquidSteel]

I had a similar issue last week in my 03.
The light came on with a chime, and then I changed the battery out. 20 miles later, the light returned with the chime. Then next morning I changed out my alternator and all has been well. Chances are, the voltage regulator in the alternator is going out, like mine was.

 

[LibertyTC]

I would scan for Obd II codes as well first.
There also is a battery temp sensor in the tray & hows the wiring there?.
A code read should point you what is wrong and the temp sensor has its own code too.

 

[tjkj2002]

I had a similar issue last week in my 03.
The light came on with a chime, and then I changed the battery out. 20 miles later, the light returned with the chime. Then next morning I changed out my alternator and all has been well. Chances are, the voltage regulator in the alternator is going out, like mine was.

The voltage regulator in all KJ's(like 99.9% of all Chryslers) is not in the alternator,it's in the PCM as a integrated circuit so if it goes bad you need to replace the PCM.

 

[CactusJacked]

Our charging system was obviously one of Chrysler's "better" ideas. If it ends up being a bad voltage regulator, you can either replace the PCM for a couple hundred bucks plus, or for $65 you can install an external regulator kit that forever bypasses the faulty and costly to fix PCM regulator: https://www.youtube.com/watch?v=utXjxwPAcHk

 

[Billwill]

You need to check that the battery terminals are clean and tight, the negative lead from the battery to the chassis is clean and tight on both ends and there is a strap that grounds the engine to the chassis that needs to be clean and tight on both ends.

Then put a voltmeter across the battery terminals....should read at least about 12.5 volts DC with engine off, should not drop below 10 volts while turning over the engine and should show about 13.5 volts at idle.

If you do not get this 13.5 volts at idle, have the alternator tested. These alternators do not have the voltage regulators inside them but do have the diode pack and the commutator brushes that could be bad.

If with a reconditioned alternator you still do not get above 12.5 volts across the battery while the engine is running then bear in mind that the thick lead going from the alternator to the battery positive terminal has a built in "fusable link" built into it which is like a large fuse....if this has blown then no charging current gets to the battery.

You probably do have a battery temperature sensor underneath the battery which can light up the same "battery" light as a charging error does. This does not really affect the charging though and if you pull codes from the PCM you will see codes for "Battery temp. Sensor" faults.