Do you know how to test automotive electrical circuits with a voltmeter ? Your alternator is not getting power where ? The only place it gets power is at heavier gage wire on the back of the alternator . Battery positive voltage . The two wires in the connector are from the PCM / ECM - engine computer . Your vehicle has what is called a smart charging system .
https://www.motor.com/magazinepdfs/042010_09.pdf
Your best bet ,take it to a qualified repair shop.
Circuit Description
The generator provides voltage to operate the vehicle's electrical system and to charge its battery. A magnetic field is created when current flows through the rotor. This field rotates as the rotor is driven by the engine, creating an AC voltage in the stator windings. The AC voltage is converted to DC by the rectifier bridge and is supplied to the electrical system at the battery terminal.
When the engine is running, the generator turns on a signal to the generator from the powertrain control module (PCM), turning the regulator on. The generator's voltage regulator controls current to the rotor, thereby controlling the output voltage. The rotor current is proportional to the electrical pulse width supplied by the regulator. When the engine is started, the regulator senses generator rotation by detecting AC voltage at the stator through an internal wire. Once the engine is running, the regulator varies the field current by controlling the pulse width. This regulates the generator output voltage for proper battery charging and electrical system operation. The generator F terminal is connected internally to the voltage regulator and externally to the PCM. When the voltage regulator detects a charging system problem, it grounds this circuit to signal the PCM that a problem exists. The PCM monitors the generator field duty cycle signal circuit.
This vehicle also has Load Shed System
Electrical Power Management
Electrical power management (EPM) is used to monitor and control the charging system and alert the driver of possible problems within the charging system. The EPM system makes the most efficient use of the generator output, improves the battery state-of-charge (SOC), refer to Battery Description and Operation , extends battery life, and manages system electrical loads. EPM has also been know as "load management" or "load-shed" in the past.
EPM performs the following 3 functions:
• Monitors battery voltage and estimates battery SOC
• Takes corrective actions by boosting idle speed, reducing system electrical loads, and/or adjusting the generator regulated voltage control (RVC).
• Perform diagnostics and informs the driver of charging system malfunctions
The EPM algorithm is run any time the dash integration module (DIM) is awake, which includes engine running, key on, accessory mode, and retained accessory power (RAP). During this time the DIM continuously estimates the battery SOC based on battery voltage, estimated net amp hours, refer to Battery Description and Operation , battery capacity, initial SOC, and estimated battery temperature. Estimated battery temperature is a calculation based on key off time, engine run time, and the temperature reading provided by the engine control modules (ECM) air intake temperature or HVACs outside air temperature.
When the EPM algorithm is running, the DIM calculates the net charge rate on the electrical system by making constant voltage measurements. It uses the measurements to calculate the charge rate in amp/hours. If the DIM detects a negative charge rate, equal to a discharge from the battery, EPM can request up to 3 levels of idle boost from the ECM, when the vehicle is in park or neutral, as well as up to 2 levels of load shedding for a total of 5 levels of corrective action to maintain proper vehicle electrical system operation.
The DIM sends a serial data request to the PCM/ECM to increase the idle speed. The PCM/ECM then adjusts the idle speed by using a special program and idle speed ramp calculations in order to prevent driveability and safety concerns. The idle speed boost and cancel function will vary from vehicle to vehicle and from one moment to another on the same vehicle. This happens because the PCM/ECM responds to changes in the inputs from the sensors used to control the powertrain. In order to maintain Idle quality the ECM may not enter idle boost for up to 120 seconds, unless there is a manual change in throttle position. There is no set time limit for the idle decrease when the criteria has been met to exit idle boost, unless there is a manual change in throttle position.
Important: The DIM also has responsibility for requesting up to 3 levels of idle boost from the ECM for the HVAC system based upon head pressure, vehicle speed, and engine running. EPM has priority over the HVAC system when requesting idle boost. However, idle boost will be maintained at the level the HVAC system requires, even though the exit criteria has been met for EPM.
