Failed alternator: no light

[w261w261]

Yesterday at a stop light, my alternator light came on. I increased the engine rpm and it went off. It did not come on again. I wondered briefly whether this was a harbinger of a failure to come, but didn't think about it again.

Today, in the midst of all the rain, the light again came on and then went off. I was 5 miles from home, and decided when I returned to put a meter on the charging system. One minute later the check engine and alternator lights came on, the car started to buck, and I was calling AAA for transport to the shop. Apparently the alternator had failed yesterday, and today I finished off the battery charge with the lights and wipers.

My question is: has anyone else experienced an alternator failure in this manner? The previous failure, about 5 years ago, was the usual: the light comes on, I drove home with no lights, and fixed it.

[InAccordance]

i drove for 3 weeks with the alt light on before it finally died on me, even then it was just the regulator as I had already replaced the brushes from a previous alt dying on me episode.
so i have the same alt ive repaired 2 times and works like a champ for now.
to hell with paying some dude 50 bucks to fix it, i'll do it my damn self!

[carotman]

Hmmm this is weird. I guess that if the alternator can supply enough voltage but no current, the light will not come on.

[ghettogeddy]

ya the one i had in my 88 did this as well light came on but went off then the next day it did the same thing but died cause i had no juice in the battery

[A18A]

vbro

[2drSE-i]

Between the three alternators my car has been through (don't buy cheap alternators...) I've never had the batt light come on. Two of my failures were as described though, lights went all dim but increase in rpms would solve it, until eventually that didn't help either

[ecogabriel]

My car did something like that but took it a few more months to blow up in smoke. First it was like it happened to you but wife (mine) was at the wheel in the middle of a bad bad storm; she made it home but battery was dead. Next day, recharge battery, start it up and no problem like nothing.... battery would slowly drain but I thought it was battery until one day it literally smoked itself...

Carotman is probably right that as long as the alt puts voltage and a minimum current it may not trigger the battery light

[AccordEpicenter]

its not unusual for alts to become intermittant when they start to get to the end of their lives

[carotman]

If the light didn't come on, it's usually from a bad regulator. This is why the lights will go brighter if you rev the car.

The regulator provides current to the ground side of the indicator lamp when it's charging. This means the light will not come up if the ground and + side have the same voltage.

If the alternator dies, the regulator is supposed to give less voltage and this triggers the light. The opposite is also true, too much voltage would trigger the light.

[AccordB20A]

ive had an alternator fuck out on me without showing the battery light also, but i knew somwething was wrong cause with the engine not running with the ignition on the battery light still didnt work.

At least it didnt overcharge your system, ive had that happen and it fucked heaps of shit in the car