SKELITOR117

iTrader: (3)

Well, took the alternator out of my car because it didn't seem to be charging the battery. Went to two different places to get it tested and both said it was good. Put it back in, made sure everything is conected, turned on the headlights and gave it some revs, and the head lights didn't get brighter or anything. I can't figure out why the battery isn't getting charged. Anyone have any insite into the problem? Thanks.

SKELITOR117

iTrader: (3)

bump.

Lucid

iTrader: (4)

You have a multimeter to test with? Take the leads and apply them to the positive and negative battery terminals with the engine running and see what the operating voltage is.

How many amps did they say your car was putting out? Sometimes these alternators "test good" but only are putting out a few amps.

How old is your battery and what brand is it?

cliff1970

check for corrosion on your battery cables. my car done this the other day and that was all that was wrong. it dont take much.

SKELITOR117

iTrader: (3)

It's got a brand new battery, and the cables are clean.

cIaRmOaCrZo

what does the volt guage in the car say its reading at assuming u dont have a volt meter?

SKELITOR117

iTrader: (3)

I think it reads around or just under 13. I'll check again later on to make sure. Assuming I do have a volt meter, what should it read?

cIaRmOaCrZo

with car running and most loads put on it, id say high 13's is acceptable. but next to no loads put on it, 14.3 is optimum and healthy

Richboll

My "brand new" battery was weak from the time I got it. Took it in to have it checked and it was replaced because it was faulty. I've had no issues with starting since.

GreenCamaro13

I would start by checking to see that the brushed of the alternator are good. not chipped or damaged. i had a story like this happen. i went to autozone to test battery and it passed, BUT it wasnt because at autozone they test it to see just enough power for that machine but thinking about it the car uses Way more power and if it has a damaged brush, it doesnt have enough power to give to the cars needs ( not just the main needed but having your radio, a/c, lights take more energy)

so brushes in the alternator is my hypothesis.

Lucid

iTrader: (4)

I would take the reading directly at the battery terminals with the engine running to get a good reading, and not put too much faith in the gauge meter. You should have ~14.5 volts when the engine is running.

I replaced the dinky CS130 alternator with a beefy CS144 140 amp alternator and absolutely love the upgrade. All my Camaros and my dads truck all have the upgrade now.

How do you know the alternator isnt charging the battery?

SKELITOR117

iTrader: (3)

Just test drove it. Seemed like it was ok. Took a reading directly at the battery. 11v at the highest, then drove it. Went to take a reading again and it had gone down to 9v. Then let it sit, and turned it off. Turned it on again and the dash said it was back at around 11. The alternator doesn't seem to be working because the battery isn't getting charged like it should, if at all. Even when I rev it to like 4500rpm it doesn't seem to be charging right if at all. Any more help would be awesome. Thanks guys!

Lucid

iTrader: (4)

If its dipping down under 12 volts, there is something definitely wrong. Check your connection going from the battery to the back of the alternator and check the actual alternator plug itself to see that it is not corroded.

I have had several alternators that "test good" but were only putting out something like 8 amps at 2000RPM during the test (should have been around 40). If the alternator is under warranty, try to convince them to swap it out. I looked at your pics, thats an autozone alternator isnt it?

SKELITOR117

iTrader: (3)

I have no Idea. But the previous owners went below cheap on everything. And they did alot of wierd stuff to the car.

GreenCamaro13

Are the brushed and brain good on alternator?

SKELITOR117

iTrader: (3)

Thanks for the chart by the way.

SKELITOR117

iTrader: (3)

I do not know.

GreenCamaro13

do you know how to check man?

lethaldomestics

Hey Check Your Belt. You should always change the belt when changing alternator.

TreeFiddy

Forget the alt for the moment, the battery can't be that low (at the terminals) unless it's flat, broken, shorted, or under a huge constant load (like starter motor cranking). Swap batteries.

SKELITOR117

iTrader: (3)

No.

Belt is good. Might change it soon, but money is tight right now.

Hmmm. Its a brand new battery that should and has been working fine. Maybe it's just that it's low. I'll charge it again using a battery charger tomorrow just to make sure. It shouldn't be under any major loads.

TreeFiddy

Unusual but not unheard of for a new batt to have a problem.

You measured right on the batt terminals themselves, not the cable terminals? Ie disconnect the battery then measure it's terminals, see what you get.

SKELITOR117

iTrader: (3)

Alright. I'll do that before I change it tomorrow. Just to be sure. And if it IS a bad battery, I have a 3 year warrenty on it, so I can just exchange it. But I HIGHLY doubt it's the battery, as it seems to be working great. Never had any problems with it. Pretty sure the problem lies with the alternator or some other part of the electrical system. How dows the Alternator charge the battery anyhow?

TreeFiddy

The alt output is a couple of volts higher than the battery's resting voltage, a bit over 14V vs the batt's 12V. Current flows from a higher voltage potential to a lower one, like water running downhill - in this case from the alt into the battery.

It therefore also flows through all the car's electrical system down to ground, which is why the alt has to be rated and able to handle the maximum sustained load the car can demand. If it can't, the battery will kick in the difference and eventually go flat.

lectric80

iTrader: (1)

Regardless of battery, if the alternator was charging the battery would have shown more than 11 volts when running. There are a couple of possible problems, and since you mentioned the PO doing some strange stuff, test the back of the alternator at the battery post on the back. How many volts when the engine is off? How many volts when the engine is running? If it shows 14V running but not when the engine is off, it may be the fusible link on that wire. The fusible link is part of the wire that comes up from the starter(normally) to the back of the alternator. It can grow weak with time, and not pass voltage normally. If this is the problem, you will need to get a length of fusible link that is the same color, cut the old out, and install new. It is not a bad idea to replace the entire wire at this point, since you are going to have to remove it from the starter to replace the link.

If it is not there, then it is going to be an issue with the alternator directly. Regardless of parts store tests, see if you can find an actual automotive electrical shop with an alternator load bench. This bench can actually test and show how many amps the alternator is putting out, parts store units simply test for voltage output. This will allow them to see if there is an issue with the alternator that the parts store test missed. I can't tell you how many cars I have replaced the alternator on after having one of the parts stores send them to my buddies shop for diagnosis. Pretty common to put them on the bench and find they were putting out little to no amperage.

The fact that voltage was down to 11 then 9 and back to 11 after having load removed, isn't really relevant to the charge issue you are seeing. Anyone who has ever driven a distance after an alternator failure can tell you how the voltage drops. The vehicle will still run, but I have personally run a battery down to 6 volts and still had the engine, computer, and headlights running, although the headlights were getting pretty dim.

TreeFiddy

I'd be getting the battery back up to charge first, to make sure it's capable of it and reduce the number of problems you're working with. Ie disconnect and put it on a charger overnight. Then chase up the alternator charge problem. At 9V I'm surprised it's still capable of cranking. Skelitor - I take it you haven't seen 14V while running yet?

SKELITOR117

iTrader: (3)

I'll see if I can find a shop near by to test it.


That is correct.

GreenCamaro13

https://www.thirdgen.org/forums/tech...-dyi-info.html

check this out,to explain what i meant.

SKELITOR117

iTrader: (3)

Thanks. I will def. have to check that out.

SKELITOR117

iTrader: (3)

Well, charged the battery today. Read a healthy 12.78 V (wasn't fully charged though). Put it in the car and started and still about 12.7 Volts. Gave it some revs while my friend metered the battery and it never changed. The alternator def isn't doing its job. I'll get it checked out pro some time when I'm free.

gsmarcano

do the "big three" electrical wiring-ground and charge wire up grades, you'll find the info here on a thread. I did it and now I get 13 plus no matter what the load.

SKELITOR117

iTrader: (3)

hah. I'll do all that when I have some money. I just spent all my cash on changing the oil. That stuff has probably been in there since 08. Maybe longer. It was black and NASTY. Glad I finally had the funds for it. Really needed to be done.

GreenCamaro13

dang, i just hope what happened to me doesnt happen to you, was driving at 7AM to work, car died about a mile away from home and had no phone. i left car and walked home. on the way some dogs started chasing me. i tried to scare them with my shoe. ran like i was a pro athlete lol. can you belive this? haha

SKELITOR117

iTrader: (3)

Haha. That's nuts. Not a DD yet, I'm hoping to fix most of the stuff that's wrong with it before I get on the road in this beast.

t-top havoc

iTrader: (3)

Stud for the battery // alternator broke on the inside or stripped from the nut?

Sorry to be soooo basic, maybe you already checked that.

K so I owe ya a dime for my

TreeFiddy

Cool, confirmed good batt.

I assume the alt was charging previously, so it's hooked up correctly?
Checked all cables, wiggled connectors, confirmed grounded ok?
What do you measure at the alt output terminal?
Has the regulator been replaced?

Apeiron

Is the battery light on when the engine is off?

lectric80

iTrader: (1)

Ok, if you do nothing else try this next:

1. Check voltage at the battery stud on the back of the alternator with engine off
2. Check voltage at the battery stud on the back of the alternator with engine running

1 should be about the same as the battery, 2 should be 13-14V. If either of these is not the case, let us know the actual readings. Either the alternator has a broken part, or more likely, the wire/fusible link from the starter to the alternator is bad.

startat2

iTrader: (2)

Its been my experience that if the wire from the battery to the alternator is bad, you will get a very low reading from ^ #2, even if the alternator is charging properly.

A quick and easy test would be to get some length of medium gauge wire and put one end on your alternator and the other to the positive side of your battery. Measure the voltage with the motor off, and then with the motor running. If the voltage increases it is your wire between the battery and alternator, can be replaced for ~ $7.

If their is no increase take a look at your alternator as the faulty component. This assumes you have ruled the battery out for any bad/weak cells.

SKELITOR117

iTrader: (3)

Thats a good Idea. In theory at least.

SKELITOR117

iTrader: (3)

Didn't see any breaks in the wire, looks to be a good conection. Little to no corrosion. Regulator has not been replaced to the best of my knowlage. Not sure if the alternator even worked when I got the car. It had a bad battery. Finally getting everything road worthy and fixed. One thing after another goes wrong. After this i have to figure out why my electric fan isn't turning on. Looks like it might be missing the sensor.

No.

Apeiron

The fan doesn't work too? Measure the voltage between the brown wire on the alternator and ground. When you find that it's zero, check the fan fuse.

JTS

Do you have any of those crimp on type connectors on the wiring going to your alternator? I've seen them get corroded inside and make a lousy connection....can't really tell unless you replace them.

SKELITOR117

iTrader: (3)

Fan fuse is good.

Crimp on... Well, there is the one wire that sort of goes on a thread peice sticking out of the alternator, and it gets sandwitched in there by a nut.

Apeiron

What was the voltage?

JTS

I was actually referring to the butt connectors for connecting 2 wires together. Sometimes the connection there gets questionable. Have you tried pulling the wiring out of the loom and seeing if there are any connections there that might be questionable. When I got my 83 chevy shortbed going it wouldn't start...the starter wasn't getting enough juice. The wire going to the starter had a factory connection where 2 other wires split off of it and that connection had gotten corroded. Once I soldered it, the truck fired right up.

SKELITOR117

iTrader: (3)

Thanks for the advice, I'll look into that as well.

Seafarer12

I would look at the wires going to the voltage regulator myself. Sounds like it isnt getting voltage to the regulator.

Apeiron

You still haven't answered what the voltage was.

kimberanton

NEVER BUT A RE MANED ALTERNATOR!!!!!! They are junk, buy a brand new one.