Alternator issues

My son got his oil changed at the local Honda. The guy mentioned he was going going to need a lot or work done. Didn't mention the power steering reservoir was almost empty or fill it. A few days later the starter went out. I replaced it then the battery light came on and it wasn't charging. I replaced the alternator and leaking power steering pump and flushed the system. Power steering is now good but still wasn't charging. Returned to O'Reilly with the rebuilt alternator and old alternator. Old failed test and rebuilt passed twice. Battery terminal connectors were loose so I added shims. I took ground connector to body off and cleaned it and reattached. Belt is good.

There is a knock sensor code. Can that be related? I've read a lot of forums trying to diagnose and that comes up a lot with alternator issues.

I checked O'Reilly and the don't carry the ELD. It sounds like this could be the issue but I'm a little confused by the diagnosis and location of the ELD.