Join Date: Feb 2009
Location: Saskatoon, Saskatchewan, Canada
Battery or Alternator?
This morning (a cool morning), about 10 minutes into a drive, I had the red battery light and the "Alternator" warning pop up on the dash display. It turned off a few seconds later, so I kept driving, but it popped up again shortly thereafter. I shifted my aeroforce over to voltage (which is good for a rough idea, not overly accurate for 'at the battery' voltage), and I could watch how it was triggering. It looked like the battery would be charging at around 13.6V, then suddenly drop to about 11.4V or lower and the alternator light would pop up. Then the voltage would pop up to ~12.8V, the light would go out, then the voltage would rise to around 13.6V again since I assume the system thought it should be in the lower voltage 'maintenance' voltage. There was never a "service charging system" or "battery saver" warning.
I'm assuming that a voltage in the low 11's while the alternator is supposed to be charging is what is causing the light to pop up. What I'm trying to figure out is if I'm having an intermittent shorting battery cell or simply a failing alternator. The battery is only a couple of months old and the startups have been nice and strong, but stranger failures have happened.
Any thoughts? Others have had similar issues, but it wasn't clear to me what was ultimately their issue.
2009 PBM G8 GT
TVS 1900 Maggie w/2.8" pulley (9-10 PSI), Maximizer LTs, High Flow Cats, LS9 injectors, Rotofab CAI, LC-2 WB, 40A KB BAP, TR6ix plugs, self tuned [250+ flashes], Camaro Paddle Shifters, UPR catch can, 4300k HIDs, Remote Start Heated Seat Control Module
, Aeroforce Interceptor Gauge, JBL GTO628's, JL 8w3v3's w/JBL P180.2, Bridgestone RE-11 tires
Last edited by Aaron407; 05-03-2019 at 10:50 AM.