did my alternator just quit?

No it's just playing possum

 

yep the battery light would come on and off and on and off.

i dont trust driving it until i get them both tested. id rather not have to tow it home again

 

I will also say that I had similar symptoms (but no battery light) on a '96 subaru impreza outback. engine would idle rough,, has no power except in surges. That was a DEAD battery (6 plus years old) and no more problems. If your battery light is at least flashing the alternator is suspect. Mine was on solid until I replaced it.

I got a Denso Reman alternator at the advice of a couple local toyota mechanics. Was $160 plus shipping from Rock Auto (with a $36 core charge - just shipped mine back today)

 

i just checked the battery, its an everstart max from walmart, date on it is September 2011

checked battery voltage with truck off (since it wont start) and it was 11.77V
checked my other vehicles and both were 12.7V

does this indicate anything at all?

i dont want to go buy a new battery and start the truck if the alternator isnt charging; ill just kill a new battery like that..

 

11.7volts means the battery is discharged or is bad it needs to be charged to test it. many parts stores [Auto Zone, Oriley's etc]. will charge and test for free.
When the battery problem is solved the truck must be running OR the alternator removed to test it. The fact that the battery is dead could be due to a bad battery, a bad alternator or both. Oh don't forget to clean and check cables [both cables and both ends].

 

Here is an old hot rodder trick... yeah I'm old..

Once your truck is running using another vehicle, grab a long regular point screw driver, butter knife, whatever you have. In the middle of the alternator on the backside, there is a cap covering the bearing, similar to a freeze plug. Carefully, engine running, lightly touch that cap. You should feel a magnetic pull, pulling the object towards the alternator which means the alternator is charging. Attempt this several times to get the 'feel' of the process. If you decide there is no pull, the alternator is dead. At that point, contact Boyles and get one that is pumped up with amperage output.

Hope this helps you.

 

this sounds pretty sketchy but ill give it a shot when i get the time to work on it.

im pretty sure theres what looks to be a heatshield? on the back of the alternator, as well as a connector. what are you referring to when you say the cap?

 

...the very center of the alternator on the back, perhaps the circumference of a quarter. Again, you should feel a magnetic tug pulling the screwdriver towards the alternator if it is charging.
Don't wear loose clothing while doing this, or a long sleeved shirt.

Be safe.

 

You stated the battery light was coming on and off. This same scenario happened to me, battery light randomly going on and off, was doing this for two, maybe three weeks...it means your alternator is going bad, a battery going bad just doesn't keep a charge/has low charge and doesn't flash the battery light when the alternator is pumping volts to the system like it should. I was on my way home 4 months ago and about 10 miles away when it finally just went south, barely had any engine power, was able to limp home with many gauges going wacko, once engine turned off, click click. Recharged battery, everything okay but battery light still on. Got reman alternator, all was good again.

This is not rocket science. Get a battery charger for the next time, replace the alternator. I have had the same charger/booster for 30+ years, there are many times it does not get used for 5 or 6 years, but then shiza happens and it rescues my ass....

Your battery is 4+ years old, you may want to consider replacement depending on the stress test results.

 

4 years, age wise, battery should be fine. On average they last between 5-7 years. Most of the batteries I've had to replace have been 10ish years old. I have replaced one that was less than a month old, dropped an internal plate and was DRT. If your charging system is poor or the battery has been abused, it might be dead but that's separate from the age.

Regardless of the outcome, buy a battery charger. Everyone should have one, if you don't need it today, you will tomorrow.

So, jumping a vehicle just bypasses the dead cars system. You're starting off the other cars battery. If your alt is dead, or the wiring between it and the battery is bad you'll get your results. A quick start and then no electric to keep it going so dead in a few seconds. If you leave the jumpers attached, with the other vehicle running, it's alt will charge your battery the same as it will charge its own. It's fine for a pinch but get a charger.

A 12v car battery in a non running car will show somewhere between high 11 and mid 12 for good/useable battery. Below 11, most vehicles won't start but old or low compression engines may. Below 10 pretty much no vehicle will start, the electric available isn't enough to turn the starter and overcome compression. Even though it will run dc electronics, it's 'dead' for your purpose. A 'dead' battery will still show voltage unless there is a complete discharge or an internal short. As I said earlier you should be seeing 14+V when the vehicle is running at both the alt and the battery itself.

Having said that, even a battery that shows good voltage may not be able to deliver the amps needed to start the car. The same with an alternator. That's where the load test comes into play, to see that not only does it carry the volts, but supplies the amps.

So, as for what your number indicate. The battery isn't fully discharged, it's slightly undercharged. It hasn't dropped a plate (voltage would be around 10 if it had) or suffered an internal short (again 10 all the way down to 0 for total failure). Which means that in all likelihood, it can be charged and be fine for quite a while yet. If it will take a charge (get a charger) and hold it, odds are its fine and the problem lies (as above) in either the alternator or the wiring between the 2. Check connections, check grounds, check your alt. It takes about 5 minutes.

*Most* dead batteries/bad alts I've had to deal with were actually bad electrical connections or dirty terminals. Clean the connections, charge the battery or jump and let the car charge it and dead batteries magically come back to life. Then go buy a charger.

 

Sounds like the alternator has seen its better day
I have had that happen to me years ago in my ZX3 and F-150

 

regarding your battery, my last 6 year battery gave up the ghost about 3 years 2 months in, very untimely...the last three batteries I have purchased, all 72 month wonders, have not made it all the way to their full warranty, although they lasted much longer than the 3/2 I mentioned...just have a stress test after charging, it will tell you a lot about the condition of said unit.

 

thank you guys for the input.

im going to call a couple local junk yards and see if they have any alternators i could pull and use, ill also be picking up a battery charger this week. any recommendations?

 

Just to get some things straight.....the battery in trucks and cars are in there for the soul purpose of starting the vehicle.. The alternator runs everything once the vehicle is started.it is a VERY BAD IDEA to pull the positive cable off while the truck is running.on newer electrical systems you will fry the voltage regulator in the alternator if its not already.just take both of them out and have them tested.. And like others have stated,clean all the connections!!!

 

oh i never planned on doing that. hopefully its just the alternator and i can find one at a salvage yard instead of buying one at full price

im curious if the magnetic pull trick works, defiitely trying that one!

 

Yes,that trick does work....a little piece of advice,you buy one at a salvage yard and you don't know what your getting.it may last a day or it may last a year.most times its better to just bite the bullet and spend the extra money up front.

 

Rebuilt alternator from advance auto, order online with 20% discount coupon and go in to pick up at the store, about $100 net after core turned in, plus a very nice warranty. How many times do you have to be told to get the battery charged and checked, and have the alternator checked at the same time. It does not take that long to remove them and pop into your local parts store and get answers.

 

i was also wondering how many people were going to repeat the same thing over and over.

like i said a few times already, i am very busy with work. im going to take them to get tested when i have time to remove both of them. no need to be rude

 

Dude, I wasn't being rude, just practical. At every good suggestion you just kinda ignore them and state what you are going to do, first you checked your battery to find it's issue date and did some voltage checking, fine, but you haven't gone in to have it charged and/or stress tested, then you just randomly say you are going to the junk yard to get a used alternator without even taking the time to get it checked...checking either the battery or the alternator (or both) is a free service at most auto parts stores. why? they want your business obviously.

Just from what you described (battery light flickering on and off) in the weeks prior to your truck taking a puke, I laid out what happened to me (a duplicate of your story), and even without seeing your truck, I am 99.9% sure it is the alternator. Heck, I drove from Virgina to Florida and back with the light flickering before it took a dive just a few miles from home, luckily able to limp in all the way back, night driving will tax it quicker, most of my driving was daytime....I got my charger out, charged the battery and all was good, zipped into town, got an alternator, about an hour later the new alternator was installed and I had a happy truck again.

Get a charger for the next time you have a problem, get the battery charged and checked, replace the alternator after they tell you yours is bad (it is) then enjoy your ride....

 

OP, I just want to add to what everyone else has said. You did ask for our help. Your battery and alternator are shot, I would bet money on it. Your alternator was going when you started seeing the light dimming issue weeks ago. By driving it until it died on you means you drained your battery all the way down, something a regular truck battery is not designed to do.

Our trucks only need a little TLC to keep running for every, yours was talking to you when the lights started dimming. If you had had the time then, to start investigating, you might have saved the battery.

That said, we have all done something like this, you live and learn.

When you get a chance to get everything checked out, let us know what the outcome was, might help someone in the future.