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Strange

Good to see a happy ending.
As long as we are here......

I have one question, and it is the part about
" something kicking on and off "
(I know very little about your vehicle.)
Is it possible that when the ECU see's a voltage drop at the battery , while at idle , it "should" trigger a high idle pull up?
I know that
On some AC systems if the engine is at idle and the clutch on the AC compressor engages, the ECU will increase the idle speed to allow the system to work properly.
This is a question for anyone that knows this vehicle's charging system.

73
Jeff
I think that is exactly what it is doing
 
@AudioShockwav - that is the event.

When you run an accessory like A/C - it's the Climate control - places quite a load on the electrical - mostly a Hair dryer to small toaster and refrigerator at the same time.

The Clutch is solenoid driven and runs off the main Harmonic pulley - so it too tells te engine it's got a load, so both Idle up for Engine and Idle up for Battery Demand takes place - tops off the battery and keeps the system from cycling the battery too harshly.

upload_2021-2-22_20-19-31.png

Life cycling of a car battery...
It's easier to think that a dead car batteries electrolyte is pure water...
When it's fully Charged, is highly corrosive Sulfuric Acid...
One of the main reasons for shortened battery life is not from overcharging - it's the lack of sensitivity to the drain to charge
  • - for the Battery is always seeking a charge,
  • when it has to deliver,
    • a chemical reaction takes place, mostly it's reversible
    • - but not without reduction
      • - you lose water; Hydrogen, Oxygen and Sulfur Ions
      • then "calcification" occurs when the sulfur binds to the lead
      • - forms a sulfate.
    • - molecule by molecule you lose plates this way from the internal resistance and the draw of power - even in micro amps
  • - that chemical reaction takes it's toll on batteries.

So when he runs the engine in a condition (off Park) Parking Brake On - yet A/C can run (runs even while parked) but in this case you may want to put it out of park and set Brake so you can put the ECM in a Drive condition - even though it's in Neutral - not in Park.

A secondary note inclusive:
The nature of long idle parking is not conducive to long engine life, so they tend to place the "Park" condition as a Closed-Loop Idle control condition - meaning that the engine will not cycle repeatedly in Idle up condition unless a specific condition in this Closed loop is demanded, it then puts itself out of closed loop (an emissions control condition of low-emission little / light load) and into an open loop condition so the Idle speed can be controlled without regards to long term idle emission issues - even though you idle for long periods of time - you're putting the ECM in a Open loop condition of power demands. (This varies amongst the makers but the premise is the same - reduce long term idle emissions as a part of reductions to Greenhouse Gasses and Toxic emissions CO - CO2 - NO2 control)

When the engine senses load, the Idle engages because again, the ECM/PCM monitors the battery condition more closely by using the Differential condition that Block ground to Frame Ground changes under loading.

And as said earlier - Battery Capacity is changing; todays technology is different from just a few years ago, and isn't going to revert back any time soon. They're too far into the battery technology to do so, the older vehicle charging systems with need upgrades soon enough because of the now different demand the battery will appear as to the charging system. The battery internal resistance is changed, and older systems relied on a large voltage drop to excite the Rotor to obtain more energy from it's field into the Stator coil winds and the field it generates from it - to generates enough change in the STATOR to push current into the battery - on top of the fact that the Battery becomes the largest Power Filter in the system - a big Capacitor taking in and smoothing out charge all the time the engine runs and tries to top off that battery - the STATOR winds itself generates the pulsed DC current - so it's never smooth even at driving speeds.

Sidebar:

So you know, most newer Diode Trios are Full-Wave - older systems were "half wave" single ended - so now use 6 diodes instead of the three.

On top of, they are mostly Schottky types allowing for more current and voltage presence upon demand. (Less power drop/losses per rotation of Rotor)
 
Last edited:
How most of these new charging systems work....

Charging System Operation
The purpose of the charging system is to maintain the battery charge and vehicle loads. There are 6 modes of operation and they include:
  • Battery Sulfation Mode
  • Charge Mode
  • Fuel Economy Mode
  • Headlamp Mode
  • Start Up Mode
  • Voltage Reduction Mode
The engine control module (ECM) controls the generator through the generator turn ON signal circuit. The ECM monitors the generator performance though the generator field duty cycle signal circuit. The signal is a pulse width modulation (PWM) signal of 128 Hz with a duty cycle of 0-100 percent. Normal duty cycle is between 5-95 percent. Between 0-5 percent and 95-100 percent are for diagnostic purposes. The following table shows the commanded duty cycle and output voltage of the generator:

Commanded Duty Cycle Generator Output Voltage

10% 11 V
20% 11.56 V
30% 12.12 V
40% 12.68 V
50% 13.25 V
60% 13.81 V
70% 14.37 V
80% 14.94 V
90% 15.5 V

The generator provides a feedback signal of the generator voltage output through the generator field duty cycle signal circuit to the ECM. This information is sent to the body control module (BCM). The signal is PWM signal of 128 Hz with a duty cycle of 0-100percent. Normal duty cycle is between 5-99 percent. Between 0-5 percent and 100 percent are for diagnostic purposes.

Battery Sulfation Mode
The BCM will enter this mode when the interpreted generator output voltage is less than 13.2 V for 45 minutes. When this condition exists the BCM will enter Charge Mode for 2-3 minutes. The BCM will then determine which mode to enter depending on voltage requirements.

Charge Mode
The BCM will enter Charge Mode when ever one of the following conditions are met.
  • The wipers are ON for more than 3 seconds.
  • GMLAN (Climate Control Voltage Boost Mode Request) is true, as sensed by the HVAC control head. High speed cooling fan, rear defogger and HVAC high speed blower operation can cause the BCM to enter the Charge Mode.The estimated battery temperature is less than 0°C (32°F).
  • Battery State of Charge is less than 80 percent.
  • Vehicle speed is greater than 145 km/h (90 mph)
  • Current sensor fault exists.
  • System voltage was determined to be below 12.56 V
When any one of these conditions is met, the system will set targeted generator output voltage to a charging voltage between 13.9-15.5 V, depending on the battery state of charge and estimated battery temperature.

Fuel Economy Mode
The BCM will enter Fuel Economy Mode when the estimated battery temperature is at least 0°C (32°F) but less than or equal to 80°C (176°F), the calculated battery current is less than 15 amperes and greater than -8 amperes and the battery state-of-charge is greater than or equal to 80 percent. Its targeted generator output voltage is the open circuit voltage of the battery and can be between 12.5-13.1 V. The BCM will exit this mode and enter Charge Mode when any of the conditions described above are present.

Headlamp Mode
The BCM will enter Headlamp Mode when ever the headlamps are ON (high or low beams). Voltage will be regulated between 13.9-14.5 V.

Start Up Mode
When the engine is started the BCM sets a targeted generator output voltage of 14.5 V for 30 seconds.

Voltage Reduction Mode
The BCM will enter Voltage Reduction Mode when the calculated ambient air temperature is above 0°C (32°F). The calculated battery current is less than 1 ampere and greater than -7 amperes and the generator field duty cycle is less than 99 percent. Its targeted generator output voltage is 12.9 V. The BCM will exit this mode once the criteria are met for Charge Mode
 
How most of these new charging systems work....

Charging System Operation
The purpose of the charging system is to maintain the battery charge and vehicle loads. There are 6 modes of operation and they include:
  • Battery Sulfation Mode
  • Charge Mode
  • Fuel Economy Mode
  • Headlamp Mode
  • Start Up Mode
  • Voltage Reduction Mode
The engine control module (ECM) controls the generator through the generator turn ON signal circuit. The ECM monitors the generator performance though the generator field duty cycle signal circuit. The signal is a pulse width modulation (PWM) signal of 128 Hz with a duty cycle of 0-100 percent. Normal duty cycle is between 5-95 percent. Between 0-5 percent and 95-100 percent are for diagnostic purposes. The following table shows the commanded duty cycle and output voltage of the generator:

Commanded Duty Cycle Generator Output Voltage

10% 11 V
20% 11.56 V
30% 12.12 V
40% 12.68 V
50% 13.25 V
60% 13.81 V
70% 14.37 V
80% 14.94 V
90% 15.5 V

The generator provides a feedback signal of the generator voltage output through the generator field duty cycle signal circuit to the ECM. This information is sent to the body control module (BCM). The signal is PWM signal of 128 Hz with a duty cycle of 0-100percent. Normal duty cycle is between 5-99 percent. Between 0-5 percent and 100 percent are for diagnostic purposes.

Battery Sulfation Mode
The BCM will enter this mode when the interpreted generator output voltage is less than 13.2 V for 45 minutes. When this condition exists the BCM will enter Charge Mode for 2-3 minutes. The BCM will then determine which mode to enter depending on voltage requirements.

Charge Mode
The BCM will enter Charge Mode when ever one of the following conditions are met.
  • The wipers are ON for more than 3 seconds.
  • GMLAN (Climate Control Voltage Boost Mode Request) is true, as sensed by the HVAC control head. High speed cooling fan, rear defogger and HVAC high speed blower operation can cause the BCM to enter the Charge Mode.The estimated battery temperature is less than 0°C (32°F).
  • Battery State of Charge is less than 80 percent.
  • Vehicle speed is greater than 145 km/h (90 mph)
  • Current sensor fault exists.
  • System voltage was determined to be below 12.56 V
When any one of these conditions is met, the system will set targeted generator output voltage to a charging voltage between 13.9-15.5 V, depending on the battery state of charge and estimated battery temperature.

Fuel Economy Mode
The BCM will enter Fuel Economy Mode when the estimated battery temperature is at least 0°C (32°F) but less than or equal to 80°C (176°F), the calculated battery current is less than 15 amperes and greater than -8 amperes and the battery state-of-charge is greater than or equal to 80 percent. Its targeted generator output voltage is the open circuit voltage of the battery and can be between 12.5-13.1 V. The BCM will exit this mode and enter Charge Mode when any of the conditions described above are present.

Headlamp Mode
The BCM will enter Headlamp Mode when ever the headlamps are ON (high or low beams). Voltage will be regulated between 13.9-14.5 V.

Start Up Mode
When the engine is started the BCM sets a targeted generator output voltage of 14.5 V for 30 seconds.

Voltage Reduction Mode
The BCM will enter Voltage Reduction Mode when the calculated ambient air temperature is above 0°C (32°F). The calculated battery current is less than 1 ampere and greater than -7 amperes and the generator field duty cycle is less than 99 percent. Its targeted generator output voltage is 12.9 V. The BCM will exit this mode once the criteria are met for Charge Mode
Great info
 
I think this is getting waaay more complicated than it needs to be. Bottom line: you want to run high power, you need one or more high amperage alternators and batteries. (Even car stereo guys know this)
Ground to frame, period.
And come to the realization that some vehicles are just not good for running high power radio communications equipment. There is a reason serious radio guys buy older cars, trucks, and suv's.
 
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There is a reason serious radio guys buy older cars, trucks, and suv's.

Many think it's nostalgic, but you do make the point - lots of parts from the older days yet lay in junkyards still serviceable -- so if it' can be bolted, = means it can be unbolted and used for another purpose.
 
I think this is getting waaay more complicated than it needs to be. Bottom line: you want to run high power, you need one or more high amperage alternators and batteries. (Even car stereo guys know this)
Ground to frame, period.
And come to the realization that some vehicles are just not good for running high power radio communications equipment. There is a reason serious radio guys buy older cars, trucks, and suv's.
I mean crazy it’s a 2 pill 1446 . What’s it draw max 20 amps ? Unreal what these vehicles have now for smart charging systems.
 
Many think it's nostalgic, but you do make the point - lots of parts from the older days yet lay in junkyards still serviceable -- so if it' can be bolted, = means it can be unbolted and used for another purpose.
Well mostly because they are old school. All solid metal, plain old motor to trans to rear end, etc. No computers, controlers, automatic this, automatic that. Just a good ol vehicle with plenty of room inside and out to do what you want
 

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