2003 Toyota Avalon XLS.The battery was installed in Aug 2013 (before I owned the car) according to the label on it. The battery itself and the connections look good with no rust on the terminals or the wire, however, I did clip and put a new, better end on the negative cause it was slightly questionable. (Still the lights flickered after that). Went to Advance Auto and had them run a battery/charge test. (all the tests were run off the battery) Results:Good batteryVoltage: 13.01VMeasured 539 ccaRated for 575 ccaTemp: 66FCharging SystemNo Load: 14.09VLoaded: 14.11V36mV RippleStill, the lights flicker. Alternator issue? I‘m about to install a 300w amp too.Hmmm. If its the alternator I‘ll obviously just replace it but would like to leave that as a last resort.
Poor ground or regulator or vibrating short!
Measure between the negative battery post and the chassis. I bet you have a missing engine to chassis ground. It could also be a bad alternator. They often test good because they get intermittent. Battery and alternator tests in shops are overrated.
