did my alternator just quit?

my 1999 tacoma 2.7l has had a light-dimming issue while driving for weeks now, i just pretty much ignored it since i drive 1.4 miles a day to work and back..

long story short: wendys drive-thru; lights on instrument panel almost non-existant, truck starts shaking violently and idles down, so i basically had to keep hitting the gas to get out of the drive thru. pulled into a parking spot and it shook no matter if i applied gas or not. once it died it only clicked like the battery is completely dead.

boosted the truck with someone elses car and it worked until i hit the gas then lights dimmed until it died again.

this makes me 95% sure its the alternator, but like ive never experienced a failed one.

would a non-functioning alternator make the truck shake? does it shake because theres no ignition source?

 

Could just be a shit battery but it's probably the alternator too.

 

i have a good voltmeter, is there any way to check the battery and/or alternator (even though the truck wont run) with that? i dont really want to throw parts at it

 

Take them out and take them to a auto parts store for testing. Your battery will need to be attempted to be charged before you'll know if its good. With such a deep discharge, even if it was good it's probably junk now.

 

okay ill probably just buy a new battery then, i dont have a battery charger unfortunately

would a bad battery dim and lights on and off for several weeks though? thats why i think maybe the alternator had a short and is now completely done

 

A good way to see if the alternator is still working start the truck and while its running undo the positive side of battery. If truck stays running then the alternator is still charging. It worked on my 5vz anyway. If it still runs then take the battery in for testing.

 

That's why i was saying both. Alternator is probably junk, stressing the battery. A parts store will usually charge test the battery. They can test the alternator too.

 

I've heard that is w good way to blow electronics on modern vehicles.

 

cant really test it like that since the truck wont start and if boosted it lasts about 5 seconds before shaking itself to death and dying

guess ill take the battery in for a charge test. so if i take my alternator to advanced auto or something similar they will be able to tell if its good or not?

 

Could be idk. My dad just told me to try it when my truck would hardly start but would stay running to check if the alternator is working. He said he knew it worked on older vehicles but wasn't for sure if it would work on the 5vz but it did.

 

Clean and check batt. cables if the lights dim at idle and brighten at speed alternator is working batt is shot or not connected take battery to parts store most will charge and test for free if batt is ok then drive to same parts store and let them test alternator or if you have a volt meter measure charging voltage when you get it started.

 

the lights dim and brighten at idle OR speed. neither one effects it. its pretty much constantly doing it from the time the vehicle is started to the time its turned off.

the drive i was doing when it finally died the lights were dimming/brightening then dimmed and never brightened again. dim dim dim until it shook itself to a stall

 

Generally, if the truck won't start its the battery. If you have a full charge and it runs down and dies, its the alt or charging circuit. The alternator by itself puts out more than enough juice to run the truck and charge the battery at the same time. If the connection between battery and alt is bad, it doesn't matter how much juice the alt is putting out, it's not getting where it needs to be. Charge the battery and troubleshoot.

With a voltmeter you should be seeing at least 14.4 on the output side of the alternator. If the output is good, you should see the same testing the battery itself while the truck is running. Takes about 10 seconds and you don't have to pull the equipment first. THe odds of having a poor connection, poor ground etc are greater than the alt being bad. Not bet your life better, but still better.

1 deep discharge, actually multiple deep discharges aren't going to turn a good battery to trash. It will shorten it's life but unless it was on its last legs to start with, it's probably not garbage.

 

so what should i clean them with? just the normal battery terminal cleaner and a brush?

 

ok thank you ill try that also

 

dont have a battery charger unfortunately. i definitely need one

 

First off go get the battery tested before purchasing a new one. The alternator on my mother's 98 4Runner died while I was out and about in it. I experienced similar issues with the cabin/dash lights being dim and hard to read. The car wouldn't turn over at all after so many attempts to start. If you tried jumping it with another vehicle and it didn't work, chances are it's the alternator. Just don't keep trying to start it after the second-third attempt because you can damage electrical components. Hope this helped!

 

i jumped it with another vehicle and it started just fine. 5 seconds later it shook real hard and died and wouldnt restart

 

Sounds like it is the alternator that is causing the issue. The battery just held enough energy to crank and then died out. The best way to find out is to have it checked or like basetaco suggested, clean the terminals. If the terminals are really corroded, it isn't helping anything so clean em. How old is the battery?

 

I just went through this a week ago, except it was a mudhole that killed my alternator, and that killed my battery. - I didn't see in your post OP, was the battery light on? on mine, after I jump-started it off of another tacoma, It would run (barely) but had no power. Took the battery to Advance auto, and it was dead - and by dead I mean discharged deeply enough it wasn't gonna recharge. It was the battery that was on the truck when I bought it, and I have no idea how old it was. Bought a new battery, that got me home, then took it to oriellys and tested the alternator - tested bad. and yes I cleaned the terminals. replaced it with a reman Denso alternator from Rock Auto and no more battery light.