I am working on a recently purchased car for a friend and would like to get it back to them. The other day I was test driving it and noticed the battery light was on (fully illuminated). Never went off... regardless of engine speed or accessories on. Voltage at the battery while runnning was <12v.
Picked up a used (tested) original equipment Denso alternator. When I put that in, the light went out... done.. or so I thought. Now it actually appears very very dimly lit. I need to check the voltage at idle. will post that later today.
Anyone know what could be causing this? What is dimly lit indicating? Is an electronic module in the alternator responsible for determining when this light should be on or off?
I went back and cleaned up the connection on the alternator lug and the wire connector, no difference. Maybe a bad ground ( at the alternator bolts/mount ) engine wires? This car is new to me and is low mileage (2004 with 115k) but didn't get the best maintenance.