2013 KIA Optima 2.4L GDI

Owner had the alternator replaced with an aftermarket and a new battery as well. He rarely drove this car and when he did battery was dead, had is boosted and it worked for a few months until battery went dead; thus the new alternator and battery. How ever after a few months, battery went dead again. He called and asked for help. I went to check every fuse for any mv readings and there was none. I checked for rodent nest and found one in the cavity where the coils were but visual inspection found no broken or nibbled wires. Next I did an alternator ripple test and the following is a shot of the waveform, which seem to indicate diode problem.



what are your thoughts about this?

Hey Robert!

That ripple doesn't look terrible to me... Less like a bad alternator, and more like an alternator that's working hard. How's the output voltage with no loads, and loads on?

I know you voltage dropped the fuses and found nothing, but does it actually have a battery draw? :huh:

Hi Tyler...at idle battery V read 14.65 and with load read about 14.2 V. Though shop said no check engine lights, I scanned and it showed faults "present" like no signal from all speed sensors, CAN no comm, drive motor steering problem...but all working. Erased all codes and drove with no fault codes.