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Check Guages light battery

32K views 4 replies 3 participants last post by  Jakyll 
#1 ·
I have a 2003 Dakota 4.7 4x4 club cab
Last night the check gauges light came on.
I looked at console and my battery gauge needle was not in the middle of the gauge. I was all the way to the left of gauge pointing to -L .
Autozone said I need a new battery, I got one, put it in, looks good,,,, drove around a little check gaugaes came back on . cleaned all contacts and nothing changes..... Help/
 
#2 · (Edited)
I have a 2003 Dakota 4.7 4x4 club cab
Last night the check gauges light came on.
I looked at console and my battery gauge needle was not in the middle of the gauge. It was all the way to the left of gauge pointing to -L .
Autozone said I need a new battery, I got one, put it in, looks good,,,, drove around a little check gaugaes came back on . cleaned all contacts and nothing changes..... Help/
The Check Gauges Lamp (if equipped) monitors:
charging system voltage, engine coolant temperature
and engine oil pressure.

If an extreme condition is indicated, the lamp will be illuminated.
This is done as reminder to check the three gauges.
The signal to activate the lamp is sent via the CCD bus circuits.

Your charging system is not working for some reason, and there
are several reasons, I'll explain them in the "check charging system steps"
below.

On the Dodge generator, there are 3 terminals:
1. The large one is the battery (output) terminal and it goes directly to the battery
via a fusible link in the PDC (Power Distribution Center)

2. There is a ground terminal on the generator, make sure it is tight

3. There are two small field terminals..these are connected to the EVR
inside the PCM. Make sure these are both tight.

Using an external voltmeter across the battery with engine running at 1600
rpm, check the charging voltage across the battery terminals
. If the
EVR and generator is working properly,
and there are no blown fuses (or the big fusible link inside the PDC is not blown),
and ALL connections are tight, and the serpentine belt
is not slipping..the typical charging voltage should be around 13.8 to 14.0 V.

How the charging system works on the Dakota..

The system is on when the engine is running and the ASD relay is energized. When the ASD relay is on, voltage is supplied to the ASD relay
sense circuit at the PCM. This voltage is connected through the PCM and supplied to one of the generator field terminals (Gen. Source +) at the back of the generator.

The amount of direct current produced by the generator
is controlled by the EVR (ELectronic Voltage Regulator) (field control) circuitry contained within the PCM. This circuitry is connected in series with the second rotor field terminal and ground.

A battery temperature sensor, located in the battery
tray housing, is used to sense battery temperature.

This temperature data, along with data from
monitored line voltage, is used by the PCM to vary
the battery charging rate.


Start by checking out the charging system.
(1) Inspect the battery condition.
(Since you have replaced the battery go to step 2)

(2) Inspect condition of battery cable terminals,
battery posts, connections at engine block, starter
solenoid and relay. They should be clean and tight.
Repair as required.

(3) Inspect all fuses in both the fuseblock and
Power Distribution Center (PDC) for tightness in
receptacles. They should be properly installed and
tight. Repair or replace as required.

(4) Inspect generator mounting bolts for tightness.
Replace or tighten bolts if required. R

(5) Inspect generator drive belt condition and tension.
Tighten or replace belt as required.

(6) Inspect automatic belt tensioner.

(7) Inspect generator electrical connections at generator
field, battery output, and ground terminal .
Also check generator ground wire connection at engine.
They should all be clean and tight. Repair as required.
 
#4 · (Edited)
So it was the generator? Usually that's what it is..either the windings inside
arranged as a Y configuration (3 windings with a common ground in the middle
of the Y, or a rectifier diode (8 of these inside the generator) or a bad bearing.
The generator (depending on whether it is a Denso or Bosch) is rated at either
117 amps or 136 amps.

There is a 140amp fusible link inside the PDC and this fuse is rated just above
the maximum generator output and is there to protect the battery from a short
in the generator, should that occur.

The PCM supplies current to the generator on the two terminals called
field and field source. This current is what regulates the charging voltage
at 14volts and the PCM also monitors the battery voltage and temperature
via a battery temperature sensor underneath the battery.

At each end of the Y winding are two power rectifier diodes, and these
are quite hefty power diodes because of the high amperage required.

If one goes, shorts, or opens up, you won't get the charging
voltage you need for the battery on the other two windings that are left.
The PCM which monitors the charging voltage all the time, will give you the "CHECK GUAGES" warning.

A catastrophic short of one or more diodes in the generator could rapidly discharge
the battery to generator ground, so there is a set of protection diodes in the
ground leg of the Y as well. Not only would a dead short rapidly discharge the
battery causing a fire in the engine compartment, but probably blow the PCM
as well, so should that occur the 140 amp fuse(ible) link from the generator
to the battery/PDC will blow first.

I would have checked the charging voltage across the battery to confirm
first, but if the voltmeter guage in the truck showed a no charge voltage,
(needle at the extreme left) then the alternator (generator) would be a
possible suspect. However there are steps that should be taken first
to ensure that it is, and I mentioned a few of them.

Anyway, glad that you solved your problem with a new generator. Too bad
you had to buy a battery to find out that it was the generator. Had you
posted here in this forum first before relying on Autozone for advice, you may
have just needed to buy a generator. But to troubleshoot the charging system you need some electrical knowledge, know how to use a digital voltmeter and most important of all..have a Haynes or Chilton manual handy
for the year of vehicle.
 
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