Thread 2932513

When I first start my truck the volt reader only reads about 10 volts and the battery warning light is on
But then I hammer the throttle and it goes to the proper 14-15 volts and remains proper for the whole drive

I am curious to know how long it will last until it totally dies out and doesnt charge it enough to run properly
So far its been doing this for 1 week and today it seemed a little worse (i had to hammer the throttle a lottle longer to get it to engage and charge properly)
So tell me about how long you ran a finicky alternator for!! The battery is 9 years old too! So i will probabaly change that too when i do the alternator!

>>2932513 (OP)
You have a broken or not connected field coil wire pic related

>>2932516
I dont see the wire in the pic.
Will i see a clear break if I inspect it

So why is it only kicking in after it gets revved up?
How long until it gets worse if i dont fix it?

>>2932513 (OP)
>battery is 9 years old
get a new battery first ya fukin dingus
the voltage regulator will act up if the system voltage is low because the battery is dead

>>2932519
Check resistance along between the battery and the alternator. It could be the relay, there could be a lamp (probably not) or the field winding might be done (new alternator)

>>2932519
Actually you only say only see one wire to your alternator? Some sort of vintage hotrod truck? Web search 1 wire alternator. Seems expensive.

The spring in the idler pulley is weak
Put a 1/2” breaker bar or ratchet in the square hole in the idler bracket…pull tight when running while someone watches the voltage. If it’s not a serpentine belt try turning the alternator by twisting the cooling fins. If it turns tighten belt…
Thank me later

>>2932537
>>2932585
>>2932533
Yeah maybe ill try a battery first but i didnt wanna cook a brand new battery

We just did the water pump, a new belt and tensioner pulley 2 months ago
Its a 4.3 vortec chevy express

Im still wondering if anyone has experience with how long a dying altrnator wil last, regardless if thats what my problem is or not

OP here
It also only does the "low voltage until revved up" about half the time
The other half of the time it starts up and is reading 14-15 at idle

>>2932542
>Actually you only say only see one wire to your alternator? Some sort of vintage hotrod truck? Web search 1 wire alternator. Seems expensive.
They are as common as the day is long. GM 1 wire alternator. About $60 bucks a piece usually. They somehow use the magnetism of the spinning rotor to excite the field coil. Sometimes if one has been sitting for a long time you will have to put a jumper between the field terminal and 12v to get it to start charging. Sometimes revving the engine up will do the trick. If you need to jumper it there is a little black rubber plug on the side where your standard 2 wire plug in will go to make it into a 3 wire alternator.

>>2932513 (OP)
9 years is an amazing and way-out-of-line lifetime for a battery - even a factory unit with virgin lead and acid. The battery's so worn, it's initially drawing huge amounts of current from the alternator and you better get rid of it quick. That battery completely quits and it WILL smoke the alternator.

>>2932657
>battery is drawing huge amounts from alternator
Yeah so im still wondering if this issue I am having . If the root cause is the battery, or the alternator
It would be nice to simply change the battery and be good
Ive driven 75k on it and when I bought it im sure it had at least 25k put on it already

in the time wasted in this thread you could have already changed the battery out
killing off hs auto shop was a crime

holy shit dude you have a 9 yr old battery and wondering whats frying your alternator? change that asap

A bad battery will kill an alternator
A bad alternator will kill a battery
Alternators are meant to keep a battery topped off.
If it is having to do double duty trying to keep a dying battery charged it will eventually burnup

>>2932698
>>2932713
Yeah so is my alternator already fried the ? Or will a new battery magically fix my low voltage on startup issue?

>>2932719
Have it tested as well as the battery.
Most part stores do it for free

>>2932721
>vortec era cebby express
ops obviously living in this van and would have to pack his sanford and sons shit collection up and steal enough gas to move camp down behind the autozone thus forfeiting his choice spot down by the tranq dealer err i mean river
if op wasnt a piss broke vagrant hed have no problem spending the whole whopping $200 on rockauto for a new alternator belt and tensioner plus another bill for a battery to be back smooth sailing again
this of course is neglecting to consider its a mid 00s gm shitbox that certainly has bigger electrical problems and would most benefit from a disconnect switch on the negative terminal

>>2932726
Damn, you are retarded and so is everyone else in this thread
My question is , how long might this last and if the root cause is the alternator or battery...
But yeah cool thanks for giving me the retarded response and tell me "haha just change it u loser!"
Lol like wow, gee I wish I could of thought of that myself

>>2932730
take it off and get it tested you lazy fucking niggerfaggot
its 2 fucking bolts a ring terminal and an electrical plug after you flip the belt off. like a 10 minute job even for a mouthbreatger such as yourself
walk into ghettozone and drop that bitch on the counter and have them spin it up on their doohickymcjigger. itll either pass check or it wont. take it to an auto electrical rebuild shop if you dont trust the parts store for some retarded reason. the rebuild shop can maybe even put a new regulator in it if its bad
but nah just keep whining on an eastern kazak reed intertwining imageboard hoping merlin can see through the spacetime continuum and identify the electron taking the undesired path in your charging system

>>2932513 (OP)
>The battery is 9 years old too
are you retarded? your battery is dead

>>2932732
Ok big brains...Can i assume you are saying its a problem with the alternator then? And not the battery?
The cute guy at autozone did test it, and yes of course his little toy says its not working,,, but then i slam on the gas and it kicks in and his device says it is working
His greasy dildo device did say the battery was good
And im going to ask again Pal, how long do you think it will last until total failure?

>>2932740
>your battery is dead
Yeah okay pal, it starts every time full cranking amps and it even shocks me when i hookup the cables to your moms nipples
A dead battery does NOT shock your moks nipples, trust me .
Lol i didnt realize DIY was so full of retards, i cant wait to troll you guys

>>2932742
using chongs dongle on with it installed is a shit test because it doesnt isolate the alternator from anything else wrong in the system like a crap battery
the alternator needs to be independently tested on something like picel

>>2932748
That machine makes me horny

>>2932748
Thanks for at least being somewhat useful in this thread tho bro

>>2932513 (OP)
Check the connectors on the alternator for signs of corrosion, mud, something that could cause a bad electrical contact

>>2932513 (OP)
Disconnect battery ground cable. Measure resting voltage. If not in battery manufacturers spec (10V is much lower than typical mid-12s and higher) shitcan battery.

>>2932609
No set longevity but yours puts out sufficient voltage to charge the battery. None of the mentioned voltages are a threat.

Ancient mechanic here who began when generators were standard. Do the math.

>>2932842
Belt slipping? Alternator belt. I know OP's pants are down past his ass.

>>2932719
Old starters put wear on the battery making them burn out quicker. So you have a bad battery, bad starter, and bad alternator. Replace all of them starting with the alternator.

>>2933686
Yeah, this the reality of having a car. I replaced my battery multiple times and my starter. Just a matter of time before I'm dealing with an alternator. Heck my serpentine belt is 20k miles old now and making me nervous.

>>2932513 (OP)
Has anyone already suggested OP get a current reading on what the alternator is putting out?
Its only about 100A or so, right?
Hook it up and switch everything on.

>short bus squad vomiting retardation instead of answering questions

Yes, if your alternator is not putting out 14 volts at idle, but does so when revving, it is failing.
There is no estimate on when it will stop putting out voltage, could be 30 minutes from now, could be when the sun explodes. Best to replace it as soon as you get a new one so you don't end up stranded somewhere.

>>2934529
It could be shitty connections, a slipping belt or a bad battery too and you can't necessarily trust op's account of what's happening. Maybe op thanks revving fixes the problem but it's just the belt gripping better after it gets warmed up. 99% it's the alternator. All the shit's right there when you open the hood though. It's not hard to check the belt, tensioner and the wiring while youre pulling the battery and alternator to get them bench tested at the parts store. It's not fucking rocket surgery.

>>2934554
Slipping belt would be obvious with sound.

Bad connections, check voltage at alternator and battery, it’s one big cable from the battery and should be simple to find a large drop from A to B.

Bad battery… a weak battery won’t cause the alternator to do that, but a totally fucked battery with dead cells will do wonky stuff, and once again that would be super obvious when you get 8.4V with the car off.

Alternators often die in a way where you only get a bit of juice when really revving them, and the put out barely anything at idle.

>>2934265
OP would need a clamp meter that can do DC. And 100A is like max. Depends what is running on the car. You see a little spike right after starting as the alternator pushes juice into a battery that just cranked the car, and then it should settle… IIRC maybe like 10A if no accessories are really running, maybe 40A-50A if you’re turning on blowers and headlights and trying to get the alternator working, and it should be able to do that at idle.

>>2934265
the loser is too poor to just buy a new battery and you want him to go out and get some specialized equipment? lol

>>2934599
I love me some DC clamp meters tho

>>2934529
>>2934554
>>2934578
I should of been more clear that the "revving it up" engages the voltage regulator and then once engaged. It runs 14 volts the rest of the drive , and even at idle
But it finnally did die after a 8 days of doing 50-100 miles daily.
New alternator is in and the battery tested fine
Should I still put a new battery in anyway?
>>2934599
Good advice

>>2936395
>I should of been more clear that the "revving it up" engages the voltage regulator and then once engaged. It runs 14 volts the rest of the drive , and even at idle
>But it finnally did die after a 8 days of doing 50-100 miles daily.
>New alternator is in and the battery tested fine
>Should I still put a new battery in anyway?
I had this same experience..
I replaced the battery because the know all mechanics checked the voltage OUT, revving up 14.1V with his el cheapo $10 DMM.
I knew it wasn't the battery, but went along with his advice spending a week doing short trips and recharging the battery with a wall charger until Bunnings got in my special order...
Turns out, no change.. Nothing wrong with the original battery, so I replaced the alternator; and problem fixed..
This is why I always recommend doing a current reading >>2934265 under heavy load to see if the regulator isn't breaking down or some of the parallel windings are open circuit.

>>2932609
>Its a 4.3 vortec chevy express
Had a Chevrolet Starcraft, belt had to be replaced regularly, or we got no charging. It didn't necessarily make a noise either.