Good evening everyone.

My 2004 Civic is having alternator issues. I originally had an issue with the original alternator overcharging so I went ahead and replaced it. After the replacement was installed I quickly checked the voltage on the battery with it running to make sure everything was working properly. It had 14v while running, so all was good and off I went to return my core. On the way back home I noticed my wipers were running quite slowly, and sure enough within a few minutes the lights started to dim and I just barely made it home on battery voltage. Pulled it into the garage, and noticed the 10mm bolt was loose, so I tightened it and figured that'd solve my issue. Wrong. I haven't been able to get it charging since I got home and I'd like to confirm a couple things and hopefully some of you gurus out there can lead me through a bit of a diagnosis.

SO: before going ahead and ripping out the old alternator (which is a pain because my truck needs a turbo right now so that's out of commission) and getting it tested I'd like to confirm everything on the car is working as it should as it is an absolute beater and things are rednecked together at best lol.

• I have battery voltage at the 10mm terminal on the alternator. But it is not charging, just stays at the current battery voltage (11.8)
• My battery light does not come on, even when I just turn the key to the 'on' position. It did, however flicker a bit on the way home, but now I can't get it to illuminate at all. (Unless I ground I believe terminal 3 on the 4 prong connector on the alternator)
• The 10A labeled alternator fuse is good, and I've replaced it with a known good to be sure.
• All other fuses on the vehicle are good, checked all.

Is there specific grounds I should check while I'm at it or wires? Or even a diagram on what I should have at the plug to confirm all connections are good?

Can't think of anything else off hand, I'd love some help. Thanks all.

 

The replacement alternator may be faulty, which does commonly happen if it is not OEM.

 

Yeah that's what I'm leaning towards in this case. This is from a parts store, so who only knows.

I'm just trying to save myself some time in case it isn't the alternator itself but it really seems like it is.

Is there any other reason why my battery light wouldn't be coming on? Throughout this whole thing my battery light really hasn't come on (other than a slight flicker at one point on the way home) and the only way I can get it to turn on is by grounding the terminal on the green plug. Otherwise even when I cycle the key all the other lights come on but not the battery light.