Hello,
I have a 97 civic LX. Battery indicator stays constantly dim when car runs. No dim or flickering lights, wipers etc. No problem with weak battery or starting car. No fuse 15 problems. Alt. belt is tight. Here's my voltage test:
car off 12.42v
car running 14.5v
car running with lights, ac on/fan high and rear defroster 14.12v

Didn't inspect wiring harness, but I don't think it would cause this symptom. If one winding went bad in alternator would I get 14.12v under load? What am I missing here?

 

had a similar issue once, typically indicates charging level barely above battery voltage. check connections for tightness/corrosion, same with grounds.

 

Is light still dimly lit in this^ case.

 

Yes. Light stays on with same dimness as long as car is running and regardless of load. Also, as previous post mentions, I did remove and Clean all battery and ground Connections. I think I found 4 if I include the smaller GA. Wire by PS pump.

 

I had to just replace the alternator in my 93 del sol si. The light was coming on dimly and my battery was near the end of its life. I replaced the battery first and the light still stayed on. A new alternator cured it. 22 year old alternator is a pretty good life.

 

i meant check the alternator connections for corrosion.

 

Okay sorry. I misunderstood. I checked alternator connections and all seem tight, no corrosion.

 

Unplug 4P alternator connector. Turn key from OFF to ON(II) [engine off].

Does cluster battery light still remain dimly lit?

 

I disconnected the 4p connector and turned the key on with engine off. The light is not on at all.

 

Replace the alternator.

 

The new alternator did the trick. No more dimly lit battery/alt. indicator light.
Thanks Ron!

 

 

Tech Q for RonJ: Would it tend to be the brushes on the alt that are the problem, or is there something else that's not serviceable that goes kaput?

 

My guess is that a bad voltage regulator caused the problem as it controls ground to the cluster light.

 

says it all. Thank you.

 

 

I am currently having almost exactly the same problem, but with a very dim battery light when engine is running and a somewhat dim (brighter than if headlights are off) when the headlights are on and engine running. After several days of research I'm at my wit's end!

RonJ, if you are still available please help me understand this issue: How can unplugging the 4-pin connector on the alternator confirm a bad alternator, since it would be disconnected during the test? Will a new unconnected non-defective alternator cause the light to illuminate during the instrument cluster check (key on, engine off)? Thank you very much for any help that you may offer!

 

Unfortunately, he has left H-T. He was great tech help.

 

OK. Problem solved! Wanted to let everyone know that the problem was with the new (remanufactured) ALTERNATOR that TESTED GOOD and was indeed charging the battery. Went to another parts store (same company) and picked up another remanufactured alternator, installed it, and no more dim battery light!

hope this helps someone...

 

Yes those chain parts store alternators are often duds.

The "battery" light is wired directly to the alternator. Nothing else controls it. If you have a 1996+ model the wire can short out behind the engine (fuse 15 TSB) which can turn the light on falsely.