I recently installed a new aftermarket alternator in my 2006 Lexus is250 and checked the battery to make sure it was good.
After installation, the charging system warning light is on and I can't figure out what the problem is.
In testing, the voltage across the battery terminals are a constant 13.85V, at idle and at 5000rpm. So the battery is charging, but not optimally, as I understand the voltage should climb to around 14.2V at higher rpm. Could this be regulator related? If so, does it indicate the wrong regulator, a blown one?