Alternator Duty Ratio

[JOMATA Lurker Find all posts View Profile Close JOMATA]

Hi all

I am having issues with the battery charging of my 2009 KDJ120, 1KD engine. Turn ignition ON, while Engine OFF, Scangauge shows Alternator Duty Ratio 31. Shouldn't it be 0?

Having alternator checked/replaced, but as I don't remember paying attention to this parameter, I'm here asking.

Cheers

[gxl_d4d Advanced Member Find all posts View Profile Close gxl_d4d]

I believe duty ratio is the % of maximum output. If you want to test this, turn the engine on and check duty ratio with high beams off then turn them on. Duty ratio should go up with lights on.

[gxl_d4d Advanced Member Find all posts View Profile Close gxl_d4d]

The regulator on the alternator might still be receiving power when ignition is on but engine off and giving you the reading you're seeing.

[JOMATA Lurker Find all posts View Profile Close JOMATA]

Alternator was replaced with a second hand genuine 100A unit. All is working fine now. Of course, the duty ratio under load is now somewhat lower than it was with the 80A unit when it was still working fine.
However, Ignition ON and Engine Off, the duty ratio still shows 31. As everything is working normal, I am assuming this is how it is supposed to be.
Just letting everyone know the outcome, should this come up to anyone else.
Cheers