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Working in Gm shop have seen numerous batteries that were new to the customer, I’ve even seen brand new acdelco batteries that were new and had problems. I Always start a diag with load test to eliminate bad battery.
Instrument Cluster Description and Operation portion of AllData found this interesting.
Battery Gauge
The IPC displays the voltage as determined by the regulated voltage control (RVC). The IPC receives a serial data message from the body control module (BCM) indicating the battery voltage. When the engine is ON, the gauge should be between 10–16 volts. The gauge will default to 0 volts if the IPC detects a loss of communication with the BCM.
Working in Gm shop have seen numerous batteries that were new to the customer, I’ve even seen brand new acdelco batteries that were new and had problems. I Always start a diag with load test to eliminate bad battery.
Recommendations on load testing? I ony have the AL539b that I know is capable of testing the battery and it passed. I haven't done the traditinal load test with the cables analog meter and a spring inside that heats up.
Can you confirm the Battery Current Sensor is creating the PWM and the BCM is providing the 5v to the sensor?
Afternoon all! I think I have found the issue. Looks like one of 3 the grounds that go to the block was broken off in the wire rap/tape.
Have repaired it and the vehicle ran for a good 30 min never charging over 15v.
Will be driving it to church tomorrow so that will be a good test to see.
Good morning, 20250621!
I have driven the Yukon to church and a couple days to work.
I am happy to report the following!
The voltmeter in the dash now reflects the homemade voltermeter.
The vehicle has not reached or exceeded 15v.
Full air and driving lights after the initial start up sits around 14.3-14.5v.
To clarify the repair!
The stud that fastens the Batt - cable to the block has an additional eye for a circuit ground. When replacing the ground cable/batt - I noticed it looked like the cable fastener should have had 2 wires crimped and it did not. After looking and peeling back the wire tape the other ground was found.
I made a ring/eyelet added it back to the stud and things are now working as they should.
Hope this helps someone!
I am glad I took all the comments, research, manuals, forums with a grain of salt and stayed on this!
My instinct said it wasn't right, however all the manuals said it was within specs.
God has blessed me with the ability to figure things out and very greatful for this !
