Charging light comes on with low idle

[HomeSkool]

Hopfully someone else has run into this problem. When my car starts the charging light stays on with low idle. When I rev it to about 4 grand the light fades and often stays away. But other times it will fade away then come right back when the rev comes back down. I changed the battery and had the alt tested and checked. Also have new batt terminals installed. Sometimes the car runs without the charge light comming on ither. It is a 50/50 chance that it will happen. But I use my stereo, Always have my lights on. Have not killed the battery ever. So I don't know if this is just a sensor failure?
Anyone have any ideas?

[takza]

You could hook up a volt meter to the battery and watch to see if the light being on corresponds to a lower voltage...if it does...then it would be the alt...or rather the reg in the alt.

I had an alt in another Japanese car that would take a while to start charging...espec in colder weather.

[Staats]

My 81 tercel with the 3AC had a similar problem - except the charge light would stay on. The alternator was defective, but could provide **enough** charge to charge the battery after each start, but not much more. The problem got worse over time. Eventually, I could not drive too long at night because the alternator was not providing enough current. The headlights were drawing more current than the alternator was producing, and the headlights would gradually dim... When I replaced the alternator (and battery, it was OOOOLLLDDD), the car ran better and the charge light went out. It is equipped with an internal regulator type alternator.

[Gasoline Fumes]

That's worn-out brushes, in my experience. You can probably replace them on the car in a Tercel. I'd just get some from a junkyard or spare alternator. Any 80s or 90s Denso alternator should have the same brushes. The brushes live under the steel end cover, which comes off once you remove the 3 8mm nuts and the plastic sleeve on the copper stud. The brushes are held in with two phillips screws. This all applies to the "modern" alt with the internal regulator. I think some Tercels had externals? I've never seen one myself, but replacing brushes on most alts is easy.

[HomeSkool]

I forgot to post my findings in this matter, Fixed this problem ages ago.
It was the Alt. It just was'nt outputting enough power. Found a cheap replacement @ Canadain tire and had it all fixed within an hour.