Alternator on my 08 went out. Battery light would come on intermittently but after driving it would go off and stay off the rest of the day.

Alternator tested bad, so I replaced it.

Now I have the battery light on all of the time. Took it to Autozone to get it tested. Battery and starting system all passed. Charging system passed Diodes test and Voltage Regulation but failed "charging current".

Battery is 14.4-14.6V when idling with no load. Alternator has the same voltage on the + stud and touching the alternator housing. Under load, I didn't drive it around but letting it idle for 10 minutes with lights, AC, stereo, interior lights on it only drops to 13.8-13.9V. It took an hour of just idling under load for it to drop to 12.4V, once I revved it up it went back up so to me under load while driving it would be working.

I have replaced all 3 grounds(battery, trans, engine) along with tried testing with a 4th ground from battery direct to engine.

ELD was also replaced.


Just took the alternator itself to Oreilly, they said it passed their test but their tester doesn't put a load on it so couldn't say if that was the problem or not. To me if it only failed under load, I would think the battery light would be off until I did put it under load more.


Need some last ditch effort advice. Not sure what else to try and check that would cause charging current to fail nor am I really sure how to accurately test, if I can, that myself with my multimeter. Have tried searching high and low but seem to be little info of issues that last beyond ELD replacement and battery, alternator, grounds all being "good".

 

i wish I had good news but the same thing recently happened to me. Put in a new alternator and it worked for a minute but then stopped charging. Had my car towed and a new alternator but it.

new alternator died shortly after (about a month or two) and was replaced by my mechanic free of charge. I think perhaps many shops just don’t do a good job at reconditioning this type of alternator. Maybe it’s the regulator that is finicky and the ones rebuilders use are cheap and die.

 

Decided to try another alternator and sure enough, seems the first replacement must have had a faulty regulator only while under load.

 

Exact same thing happened to me... First replacement light on all the time, second one fine. I got a Bosch one thinking it would be better than a no name, but sounds like a common issue...

 

Oddly, I bought a Bosch thinking the same thing.

Grabbed an AC Delco instead that worked.

 

FYI, Honda OEM alternator (Denso?) goes for 1500$ in Canada now. Yes you read correctly, 1500$. So it might be worth keeping that sucker. I’ve heard you can bring your alternator to a shop and have it rebuilt. That might be worthwhile since the part is so valuable (compared to its 50$ core charge).

 

Hi, I'm having the same problem. I think it is the EDL from what the internet says. It's a $168 in Canada. If your voltage is supposed to be 13 and a 1/2 or higher when the engine's running, then the alternator technically is fine. Someone on the internet said the brushes in the alternator are going, but it doesn't make sense if it's putting out the right number.I'm assuming it's the electronic load device. It's a bit of a pain to get to and it's cold here in Canada. I can't seem to attach a picture, but it's in your fuse box which is on the driver's side on the left side.you have this drop down drawer. And I'm not exactly sure how you take it out and replace it ...not yet anyway.

 

I just saw that someone replaced their EL. D. And they still have the same problem. And I just posted that that could be the problem. That's weird ....Honda charges a 180 to do a scan.

 

People never learn, just cuz part has been replaced doesnt mean its good. Also people should learn alternator and battery testers at auto parts store suck. Refurbished alternators are rarely refurbished to level that you assume. They get new bearings, body gets painted and its sent on its way to store after rudimentary test. Thats it.

 

I didn't know you're supposed to rev the motor because the alternator can actually lose power as the arms go up.