battery light on, comes and goes Options

[nics]

hello peeps!
So last Friday, I drove down to SoCal and after 420 miles, battery light came on. I pulled over, turned off the car and started it again, battery light came off. Then after driving another 25 miles, it came on again. And then I did the same thing, turn off and on the car. Worked the 2nd time! I got to my destination which is 15 miles more. Parked the car, called it a day.

After 12 hrs, started the car and viola, battery light remained on. I took it to autozone to have my battery and alternator tested. Autozone charged the battery first because it was 71% only. While in diagnosis, the guy made me start the car and miraculously the light wasn't on. The battery and alternator checked out ok.

So I decided to take the car for a spin, about 10 miles of driving light came in again! I pulled over, did my trick and it work. On my way back to my apartment, it came on again but when I exited the freeway, I went on a stoplight and when it turned green, battery light went away! I went to my parents house which is about 15 miles and back, battery light didn't come on.

Is my alternator going bad or my battery?
Are there other ways to test my alternator?
Is it possible that the belt could be the culprit? -Belt looks ok and tension seems right
What other things do I need to look at?

note: driving ~70mph when the battery light came on (driving to my parents' house ~70mph battery light didn't come on).

Need help to figure this out and fix it. Thanks

[richee3]

Battery light is the alternator. The alt is probably going bad. If the light wasn't on when Autozone tested the alternator, it makes sense that it would look good when they tested it. It's a strange problem for sure. I doubt if it's belt related or you probably wouldn't have a/c either.

[stephen_lee]

check the wiring going to the alt. esp the 3pin connector.. id bet its loose.

either way clean up the 10mm post on the alt.

[nics]

checked the wiring, it's still intact.

[xrav22]

checked the wiring, it's still intact.

Alt going out, an old car I had went for weeks with light on, then it just died. The bushings worn or diodes failing slowly.

[nics]

what brand should I get? How reliable is duralast from autozone?

[stephen_lee]

ALL aftermarket parts stores are the 70a version... that said i have one on my auto daily and its OKAY. my system full blast, high beams, and fogs dip it below 13v while driving, though... so in my case I need a higher output alt, or DUAL.

[trdproven]

i saw that battery light come on, in a 5sfe camry, it was definitely the alternator on that one, so it is an idea to check it out.

[richee3]

Why buy a new one? Just get the factory alt rebuilt. It's like $50 and I trust it more than cheap aftermarket alternators.

[stephen_lee]

Why buy a new one? Just get the factory alt rebuilt. It's like $50 and I trust it more than cheap aftermarket alternators.

yeah. Toyota rebuilt alt are comparable in PRICE to parts stores alts.

[nics]

bought one, installed, drove 500 miles on it. I needed it to get back to norcal. Costs me $140 +$20 for the belt.

where do I get the toyota rebuilt alt? Dealer??

[stephen_lee]

yeah


the dealer

[trdproven]

like what stephen said, on my celi, the alternator harness got brittle and got loose, and the wires werent holding on tightly like dangling wires, i found this when i had a notion it cannot be the alternator so I pulled the wire loom back and there it was the plastic harness all falling apart.

[richee3]

Nah, I didn't mean go buy a rebuilt Toyota alternator. I meant get the one you have rebuilt. I had mine done, cost $50, better than new.

[trdproven]

almost all if not all things from napa are rebuilt at least in my area.

[nics]

yeah


the dealer

I didn't had a chance to check my local dealership but I looked it up on 1sttoyotaparts and its like $150. It's a rebuilt alternator.

like what stephen said, on my celi, the alternator harness got brittle and got loose, and the wires werent holding on tightly like dangling wires, i found this when i had a notion it cannot be the alternator so I pulled the wire loom back and there it was the plastic harness all falling apart.

I noticed that too that my harness is kinda crusty.

Nah, I didn't mean go buy a rebuilt Toyota alternator. I meant get the one you have rebuilt. I had mine done, cost $50, better than new.

Oh I see. Well I didn't know how long would it take to rebuilt it and I was running out of time. Now I know!!

[trdproven]

if you need a replacement harness just go to a junkyard, take a sample of yours, or a picture, or remember the type of harness, and at the junkyard, you can look for any compatible toyota that is the same harness type, i know for sure that the mid 90s corolla is the same.