Welcome to the Seneca family on JOF.
When you turn the ignition key to run (before moving to start) a number of things are causing a heavy drain on your batteries in preparation for starting.
You will see the Intake Heater lamp on the dash illuminate as these components are preparing to start. Your voltage reading on the dash will fluctuate back and forth as the intake heater system is cycling on / off. Once we see the Intake heater lamp go out, we then will start the ISB.
Once the engine starts and until the running temperatures are no longer requiring the intake heater system, then you will see the voltage cycle back and forth. When the intake heater cycles on, we often see our voltage readings in the 12.4 range. Research indicated that the two intake heating components draw 95A each.
Once these systems are at temperature... all normalizes.
Steve & Stacy with Jasper (Australian Cattle dog)
2015 Seneca 36FK
Custom 27' flatbed trailer hauling:
07 Toyota FJC & Yamaha Kodiak 400 ATV