Hello everyone I joined the group because my dad owns a 2006 Accord LX auto trans.

Recently he had to pull off the road because his battery light came on and modules were dropping off like the airbag light and abs.
I checked voltage at the battery and it was 12.6. When the car was running it stayed the same battery light still on. I ended up driving it home had to stop once to charge it off my car.

Where I'm at so far is that I had the alternator tested at autozone and it passed they ran the test twice. At the 4 pin he has 12v on black/yellow 5v on the white/red wire approx the same on the blue white I believe, but he has nothing on the green/white altc. I tested the output lug at the alternator and he has nothing there. Pulled the fuse panel and the ELD sits at 5v on ignition on and running its fluctuating at 3.8v approx which appears normal to me. He currently does not have a upstream o2 but its been like this for weeks, we ran it up to autozone on battery power to have them pull codes and it only came up with two o2 codes.
I have several OBD readers but Im thinking I need to get HDS to be of any real help.

​​​​​​Today 9/9/2021 he broke down again this morning same symptoms head lights dimmed and he started loosing power rapidly. He had power all the way up untill he started hitting rain and the car got wet. At this point I dont know what to do besides put another Alternator in. LKQ has it for 60 dollars off a car with 70k miles. I dove the car all around town yesterday to test it and it was fine this is driving me nuts. I pulled number 18 fuse it was fine and disconnected the gray harness on the right side of the motor, disconnected the eld harness and reconnected, its hard to say what got it charging all day yesterday.

 

So the battery voltage read 12.6V with the engine running?

What voltage do you read between the large cable at the alternator and the + battery terminal when the engine is running?

 

The first time I checked the battery when I got to where the car was engine off thats the first thing I did.

I read the voltage off the alternator lug when I got it home and tested it was at battery voltage I want to say 11 something it dwindles rapidly I will start it, the battery light goes out and then it continues to drop untill it gets to low 11's even 10 something light comes on before I shut it down today testing it. It was on the battery charger all day before I met him today to put the battery back in and drive it home again. The crazy thing is how I drove it all around town the other day and it was fine thats the first time it had worked for a few days, I cleaned all the connectors in the underhood fuse box, thats when tried testing and unplugging the eld. When I had 14 it didnt matter if the eld was unplugged but today when it was not charging disconnecting it did not make it charge. I thought maybe it would get the ecu to disregard the load circuit stuff.

 

The voltage across the battery with the engine running should be >13.3V. The voltage test between the alternator lug and the + battery terminal should be zero. If you have voltage (>~1 volt), then the wire/connectors between the alternator and battery can the issue.