my battery light stays on my dash now never did before alternator seems good and i went 300 plus miles any ideas guys or gals?

 

i had the same problem several years ago with my toyota
took it in to a alternator specialist .
it was putting out 14.8 volts, but it was not generating any amps at all.
the weird thing is? even the shop was shocked ,, they had never seen a alternator pump out volts but no amps.
go get a re-built alternator.

 

had a reman alt on my truck do that to me earlier this year
ended up being Alternator as well!
Damn optima redtop runs forever lol!

 

thx

 

I left the house one morning with the battery light on hoping i could get it to work and figure out the problem, but I didn't make it very far. Alternator was toast and my battery was junk and I only made it about 5 minutes.. lol

 

Same thing here with the battery light, but mine turned out to be alt. was over charging.

 

imo overcharging is worse. can damage /fry other components.

 

yea sounds serious im going to get a new alternator asap thanks dudes

 

before you go replacing the alternator-
put a voltmeter across the battery terminals - at idle it should read about 13.8 volts if the alternator is good. then rev it to 3000 rpms or so. should read about the same.

i got an alternator a year ago from a junkyard. $25.- .. still working ..
easy to pull out 3 bolts.

 

Give your battery a check too. I still have my original alternator, but I replaced the original Motorcraft battery last year. I haven't had my battery light come back on since. It's either going to be your alternator or battery.

 

yep load test the battery.

 

I have had this happen to me twice this past year! I was driving and my volt gauge was going down, pulled into Auto Zone and the truck died. I has a spare alternator on me so I just replaced it in the parking lot lol. The other day, the opposite happened. The voltage regulator busted so I drove over an hour home to get the regulator off the old alternator. When I popped the hood...battery acid everywhere. I Replaced the regulator, put the battery caps back on and it has been working fine ever since. I would recommend picking up a motocraft battery with the alternator.

 

so the overcharging situation actually blew the caps off the battery? wowza

 

Had the voltage regulator blew in my dads F-150 and the damn battery blew up.

 

battery light has nothing to do with the actual battery. Problem is the alternator.

 

load testing the alternator wouldn't be a bad idea either... i can't remember exactly how to do that, but it's not much different than testing the battery, i think you just do a battery test, but there is an additional lead, looks like the clip you put on your spark plug wire, for a timing lite, except you put it on the positive lead? if you know someone with a charging system tester, they will know how to do it

 

yeah but if you rev it up and it still reads normal then the alt. should be good.
someone else had an alt. that tested normal at idle but way overcharged at 3000rpms.

i had a battery blow up even though the alt. was good. a couple plates shorted inside and it went kablooey. it was not a pretty sight.

 

nah, as said before, you can have volts fine, but no amps, which is why you need to load test it

 

Thats what mine did. NEVER let parts store check your alt. Took it to a alternator specialist and he fixed me right up.

 

well you can always load test both and then 2 minutes down the road the things pack up lol
may alt was testing fine but making this horrible screaming sound at around 3000 rpms..
replaced with one from a junkyard for 25 beans.. still working a year later

left the old one on the bench and within a week i couldn't turn the pulley the bearings were shot.

 

My battery light tonight would turn on then off in more of a blinking pattern. I will be checking the alt and battery this week-end.

 

maybe it's blinking in code, lol
3 short,3 long, 3 short = SOS

 

don't be dumb, the guy is asking for help with his truck

 

don't be so serious!!

i didn't see a question there..

could be a lot of reasons a batt light intermittently goes on/off...
without some further info for example what voltage is the alternator putting out? it's a tough thing to diagnose.

so chill until the OP gives some info ok?

 

i'm just fine, and you are right that he needs to post more information, but you don't need to make fun of him...