Circuitry, charging, how to tell if you need a new battery.

Congrats, you have found Ford's super secret fuse that drove everyone mad for years!

Bad Battery? Need details on car,engine, year, etc. don-ohio

What do you mean won't stay charged ? Battery dies while driving , dies over night ? Is the battery symbol lit on the dash , check charging system message on driver info center ? If it drains over night there is a parasitic draw on the electrical system ! If while driving the battery goes dead it's not charging , with a new alternator the problem is in the electrical circuitry . Blown fusible link or fuse . This charging system is controlled by the PCM - engine computer , the heavier gage wire on the back of the alternator should have battery voltage , if not blown fusible link near the battery . The connector with three wires ,one should have B+ voltage , the other two come from the PCM .

Dear Joyce,
The "battery not charging" light actually will tell you many things, and that one light is affected by several parts of the car.
If your battery is new, then the light is telling you some other part of the charging system is failing or has failed.
The most common part is the alternator.
The alternator, or the voltage regulator which is built inside the alternator, can both fail, and the light is telling you.
Those need to be checked by a repair man. (mechanic)
If you have no corrosion on the battery terminal, or the wires, or inside the insulation of the wires, the alternator should be your problem.
God bless your efforts.

The portable charger should NOTE be connected to a battery while the battery is connected to a vehicle! Charge the battery off the car, then disconnect the charger and put the battery into the vehicle to start it! If the charger is not working check the fuse! If that is ok then probably damaged the circuitry!

You need to go to auto parts store and have them check that the alternator is charging the battery. They do this for free. Also have them check the battery to make sure that there is not a bad cell in the battery. This can happen from time to time. if all of that is good u may have a drain on the battery. Check that all lights go out when u shot down the car.

ALTERNATOR DRIVE BELT SLIPPING OR BATTERY CABLES NEED REPLACING IF THEY ARE THE ORIGINAL ONES.THE VOLT GAUGE COULD BE FAULTY.TO TELL GET A DIGITAL VOLTMETER HOOK TO CAR BATTERY CRANK CAR UP.BATTERY VOLTAGE SHOULD BE 13.5 TO 14.5 VOLTS. WITH NEW CABLES. IF NOT CHECK ALTERNATOR FIELD WIRES FOR DAMAGE ALSO ALTERNATOR POSITIVE WIRE FOR DAMAGE.

a battery waring ligth is not telling you that the battery is defective, it is telling u that the battery is not being charged by the alternator, have the battery and alternator tested to determine th4e cause, a failing battery many times can damage the alternator as it causes it to overheat, so if the alternator is in need of replacing then it is very important that the battery be fully charged and tedsted prior to installing a new alternator if indeed that is the final diagnosis.

Hope this is helpful, Ian

CHARGING
DESCRIPTION - CHARGING SYSTEM
The charging system consists of:
† Generator
† Decoupler Pulley (If equipped)
† Electronic Voltage Regulator (EVR) circuitry
within the Powertrain Control Module (PCM)
† Ignition switch (refer to the Ignition System section
for information)
† Battery (refer to the Battery section for information)
† Battery temperature sensor
† Voltmeter (refer to the Instrument Cluster section
for information)
† Wiring harness and connections (refer to the
Wiring section for information)
† Accessory drive belt (refer to the Cooling section
for more information)
OPERATION - CHARGING SYSTEM
The charging system is turned on and off with the
ignition switch. 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 generator is driven by the engine through a
serpentine belt and pulley or decoupler pulley
arrangement.
The amount of DC current produced by the generator
is controlled by the EVR (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 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. This is done by
cycling the ground path to control the strength of the
rotor magnetic field. The PCM then compensates and
regulates generator current output accordingly to
maintain system voltage at the targeted system voltage
based on battery temperature.
All vehicles are equipped with On-Board Diagnostics
(OBD). All OBD-sensed systems, including EVR
(field control) circuitry, are monitored by the PCM.
Each monitored circuit is assigned a Diagnostic Trouble
Code (DTC). The PCM will store a DTC in electronic
memory for certain failures it detects. Refer to
On-Board Diagnostics in the Electronic Control Modules(
Refer to 8 - ELECTRICAL/ELECTRONIC CONTROL
MODULES/POWERTRAIN CONTROL
MODULE - DESCRIPTION) section for more DTC
information.
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 PCI bus circuits.
The lamp is located on the instrument panel.
Refer to the Instrument Cluster section for additional
information.
VOLTAGE REGULATOR
DESCRIPTION
The Electronic Voltage Regulator (EVR) is not a
separate component. It is actually a voltage regulating
circuit located within the Powertrain Control
Module (PCM). The EVR is not serviced separately. If
replacement is necessary, the PCM must be replaced.
OPERATION
The amount of DC current produced by the generator
is controlled by EVR circuitry contained within
the PCM. This circuitry is connected in series with
the generators second rotor field terminal and its
ground.
Voltage is regulated by cycling the ground path to
control the strength of the rotor magnetic field. The
EVR circuitry monitors system line voltage (B+) and
battery temperature or inlet air temperature sensor
(refer to Battery Temperature Sensor or Inlet Air
Temperature Sensor for more information). It then
determines a target charging voltage. If sensed battery
voltage is 325 mv or lower than the target voltage,
the PCM grounds the field winding until sensed
battery volage is 325 mv above target voltage. A circuit
in the PCM cycles the ground side of the generator
field up to 250 times per second (250Hz), but
has the capability to ground the field control wire
100% of the time (full field) to achieve the target
voltage. If the charging rate cannot be monitored
(limp-in), a duty cycle of 25% is used by the PCM in
order to have some generator output. Also refer to
Charging System Operation for additional information.
REMOVAL
The electronic voltage regulator is not a serviced
separately. If replacement is necessary, the PCM
must be replaced.

RECHECK the New Alternator This is Not Unheard of as I Have Experienced it Myself Several times.
After RULING it out and the Fallowing,Main relay box Power terminals, Corroded Loose fit nuts Etc.
Consider Voltage Regulator, Read the fallowing "CAREFULLY"

CIRCUIT OPERATION
The Electronic Voltage Regulator (EVR) is not a separate component. It is actually a Voltage regulating circuit located within the Powertrain Control Module (PCM) . The EVR is not serviced separately. If replacement is necessary, the PCM must be replaced.

Operation: The amount of DC current produced by the generator is controlled by EVR circuitry contained within the PCM. This circuitry is connected in series with the generators second rotor field terminal and its ground.

Voltage is regulated by cycling the ground path to control the strength of the rotor magnetic field. The EVR circuitry monitors system line Voltage and battery temperature (refer to Battery Temperature Sensor for more information). It then compensates and regulates generator current output accordingly. Also see Charging System Operation for additional information.

FOR Detailed Diagrams,on Entire Charging system they Must be Emailed,as they are too Large for the Formatting that "FixYA" uses my Email add. is My nickname here but add @aol.com By all Means If this is of Help to you , Then PLEASE RATS Me Thank you and have a Blessed DAY rejakwilson