So a few months ago my alternator started to go. The battery light would be on, and would only turn off after driving for a few minutes, and at 2000+ rpms. Purchased an alternator from RockAuto, did the install about a month ago. After that, the light would just intermittently come on. Drove it to an Autozone, they said, battery has some bad cells due to the intermittent charging when the alternator wasn't working properly. Ok, put in a new battery today, and the light is still randomly coming on.

Any thoughts?

 

Get your voltmeter on battery posts and check for voltage when the light is on.
DO IT ON IDLE in park or neutral (not when driving because dual mode charging system typically put alternator to "sleep" mode when no power demand is present)
If during the "light on" time it drops to 11.5-12.0 volts on idle
check the alternator 80 amp bolt on fuse under positive terminal cap for corroded connections, etc
If fuse is fine the alternator or wiring may be defective.
Many late model rebuild alternators are painted over junk with replaced brushes or made in China bearings, then put in nice box and sold at discount price.
These alternators are not tested for intermittent issues.

 

Good advice, except my observation is, the 'sleep' mode typically happens at idle.

So, I suggest keeping the alternator 'awake' at idle by testing with lights on, and interior fan at HIGH.

Should still be more than 14VDC, even at idle.

^^^ Amen to that. I always bring starters and alternators to my local auto electric shop, so that they can rebuild AND TEST my existing part.

 

My car is automatic, so stick shift may have a different set up; I notice it when idling in D with brakes applied (all accessories off)

 

Get yourself one of these and stick it in the accessory plug. With it you can check the alternator voltage at any time. It will help diagnose your problem. These are so cheap that we have 8 or 10 laying around the garage and our hangar and in some of our vehicles. You would be surprised how often we use one .

https://www.aliexpress.com/item/LED-...2-bfbbbd6dc6de

 

Thanks for all the suggestions!! I should have time on Sunday to play around and hopefully figure something out.

To add to the fun, if I turn my lights on, or turn the fan on to 3 or higher, battery light never comes on.

@n9cv, where exactly is the "accessory plug"??

 

ELD malfunction?

 

Electrical Load Detection? Where and what is that?

 

https://www.civicforums.com/forums/2...-detector.html

It's #11 in the GE diagram below (looks like a relay)

 

So yeah, lil lazy but finally had the chance today to replace the ELD in the fit. Drove it around afterwards for about 10 min, the battery light flickered once about 2 min into the drive and not again after that.

That worries me that I have other problems, but at least I don't have to drive around with my fan on max (crossing fingers)

Thanks to everyone for the help, hopefully this is the last post in this thread...

 

Spoke too soon. It's back. At this point, I think I have to bring to a shop, I'm tapping out

 

so what was the outcome ? what ended up being the problem?. (I'm having the exact same issue)

thanks!

 

I can speculate that flickering light comes from worn brushes in alternator. Bad regulator will give a solid light.

 

Sadly it was the alternator. I got a replacement, and that was bad too, so it ended up being another 2 months of changing parts that didn't need to be changed. Super frustrating

 

Many late model rebuild alternators are painted over junk with replaced brushes or made in China bearings, then put in nice box and sold at discount price.
These alternators are not tested for intermittent issues.

 

I'm having the same problem. I got a replacement alternator in april 19 the flickering started Again a week after. I ignored it it went away for 2 months and in August (yesterday) it finally shit the bed. I bought a new battery and used it to take it to the shop ( battery light sold on still) where I declared the alternator they gave me was defective. I have a 2012 the original alternator lasted 7 years the rebuild is garbage and lasted <7 months. I'll let you know how that works out for me. Hopefully it will help.

P.s. there didnt seem to be a correlation between rpm, speed or time driving to the battery light. After 5 months the battery light became more frequent and the headlights would flicker. I hope it's not the ELD cause i have no idea what that is and if my mechanic will.

 

Well the shop will have a good time This is when someone asks me to help changing the alternator, I am asking potential customer to buy a certain quality brand from specific auto parts store. Typically I never see these people again but I'm not doing it for living. Ideally , either dealer or junk yard is your friend

 

My Honda Fit is also a 2012. When the rpms get up to 8 or 9 on the dial, the red alternator light will flash on and off a few times. Then I take my foot off the gas and coast and the light goes off. Interesting that we have the same year model Fit.