new alt. new battery, still getting a drained battery

[mrowe87]

So suddenly my car stopped starting, get a jump starts fine, shut if off click. Got a new battery, started fine for a while, click!!! Got a new alternator, started up, shut it off, click, threw it on a charger, worked fine for a day and a half, suddenly today got the click again. I checked my fuses for a crazy draw, its not there! At around 400 dollars for a battery and alternator and the same problem, any ideas, anybody?? I dont think this helps anything, but its a 99 318ti

[ApexEight]

Voltage regulator?

[mrowe87]

thats internal on the alternator, thats what they told me was bad on my old alternator which is why i purchased a new one

[Beitie]

You have something that is drawing power. You'll have to track it down. Could be a light that won't turn off, or something else.

[mrowe87]

its something more draining than a light as my car ont start immediately after shutting it off sometimes. so its as if it not getting charged up, but the alternator is days old. and its intermittent

[mgoods50]

You need to go by a parts store and have them check both the battery and charging output, eliminate the obvious first , even if both are new.

Intermittent could be poor ground or poor connections at starter, battery, alt. or all.

[mrowe87]

yeah i just went to auto zone and they said they couldnt even test it because it was showing only like 12.2 volts when it was running! does this mean i need to utilize my LIFETIME WARRANTY and do the fantastic fun job of removing/installing another alternator?? or could there be another issue here?

[mgoods50]

Means you need to stop buying auto zone alternators.

bnrparts on ebay rebuilds them. They do high output rebuilds, don't know if they do regular. I don't have any affiliation other than professional. I can tell you they are decent people and do good work.

Alternatively, pick one up from a yard. Anything is better than parts store and it seems lately there are more and more negative issues. Keep in mind it's not their "fault."Whoever is buying them is specifying cost etc. Kinda like the Chinese parts discussion.

Just for comparison, a few years back I kept getting bad radiator temp switches. Went through FOUR. #5 was ok. All new, and happened to be oem supplier. Point: always check the obvious first. New means nothing.

[jmo69]

A new alternator should be putting out close to 14 volts at idle. I went a few rounds with alternators from Advance Auto parts with my e46. The first one was bad right out of the box (bad bearing) second one lasted 18 months and the third 14 months. Unfortunately the lifetime warranty only applies to the first one and the second only gets 90 days. In my case the second one had the lifetime and third didn't because the first one was bad to begin with. Consider getting your money back and buying a Bosch (if that is what you had originally) from FCP and get a real lifetime warranty on an OEM part. One other thing, does your battery light come on when you turn the key to position 2? Some alternator systems won't work because that circuit excites the field IIRC.

[mrowe87]

well i just dug my old alternator out of the trash tok it up there to auto zone and they told me it was fine. so i took the new one off and put the old one back on, but its still idling at 12.8 volts? idk what my cars sickness is

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also after going and driving for about a half an hour with my old alternator that tested fine at auto zone, i parked my car and immediately attempted to start it, and CLICK CLICK CLICk.

[shogun]

Must be something different than the starter motor itself.
BBA-reman info on : BMW Starter Motor Problems and Faults http://www.bba-reman.com/content.aspx?content=bmw_starter_motor_faults_and_ problems







No Start Caused by Faulty Oil Level Switch

[mrowe87]

my battery isnt getting charged. my starter starts just fine, did you mean alternator motor? cause it also starts fine with jumper cables or a trickle charger on my battery, any ideas??? anybody?

[mrowe87]

1999 318ti, new alternator, new battery. Car worked fine for a day and then suddenly started not starting again. so i took my old alternator to get tested and they said it tested fine, I reinstalled it, checked my wires at the started, and they were tight, everything is installed right but my car isnt generating power to recharge my battery. Ive just come across some hints that my symptoms could be a bad DME? does anybody have any insights to this situation

[flyfishvt]

When you turn the key in the ignition does the battery light come on with all the other warning lights ?

[mrowe87]

oh yea it does

[jmo69]

How does the battery test out? I can't imagine anything draining the system that fast. The voltage at idle should be higher than 12.8, if that was the battery voltage at rest it would be good. I think what Shogun means is your starter might be drawing more than the system can provide, I still think it's the battery.

[flyfishvt]

Your alternator may not be grounded correctly. Some alternators ground through the case. Get a set of jumper cables. Attach one end to the case of the alt. Attach the other end to a strut bolt or somewhere else on the engine. See if that gives you a good reading at the battery while the engine is running.

[jmo69]

What is the battery voltage before trying to start the car? I'd still take the battery in and have it tested.

[mrowe87]

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I just went back up to autozone with my New starter, and it tested just fine, they did give me a new battery, i just threw the multimeter on there and it was idling at about 12.2 volts? can this be a dme issue?

How does the battery test out? I can't imagine anything draining the system that fast. The voltage at idle should be higher than 12.8, if that was the battery voltage at rest it would be good. I think what Shogun means is your starter might be drawing more than the system can provide, I still think it's the battery.

[mrowe87]

you saying just attach a cable to any where on the metal of the alternator, and with the opposing end of the same jumper cable alligator clip, attach that to a bolt? I just dont know what you mean alternator case, and id like to give this a try cause nothing is really working. dunno if this help inquiring minds, but when i rev my engine,my volts do increase at the battery, to around 13.4


Your alternator may not be grounded correctly. Some alternators ground through the case. Get a set of jumper cables. Attach one end to the case of the alt. Attach the other end to a strut bolt or somewhere else on the engine. See if that gives you a good reading at the battery while the engine is running.

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it varies from like 12.2-12.8...... but when i turn my key it has dropped to 8 this one particular time I was looking at it.


What is the battery voltage before trying to start the car? I'd still take the battery in and have it tested.

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even with this newest new battery i pulled in the garage and grabbed the multimeter hoping to see something different and resolve to this issue and it was idling at 12.2 volts. so im pretty sure Ive solved absolutely nothing at this point

[flyfishvt]

Varies from 12,2-12.8 sounds like a bad voltage regulator or bad alternator. Get it tested somewhere else.

[JDStrickland]

Disconnect the negative battery terminal and move the cable aside. Now you can go through the car and follow the red battery cable to make sure all connection points are tight. When the negative terminal is disconnected, there is no danger of arcing when the positive cable touches the frame via the wrenches you are using.

There is a connection on the back of the alternator that goes to the starter. The power tap on the back of the starter has a cable that goes to the B Post (jumper terminal inside the engine bay). There will be two large red wires on the starter, one to the alternator and the other to the B Post. On the back of the B Post, there is a cable that goes to the battery compartment.

You are describing a loose connection somewhere on the fat red cable. Off of the positive battery terminal is the fat red wire that goes to the alternator, via the other points I mentioned, and a smaller red wire that goes to the fuse buss to power the vehicle systems. Your issue is in the charging circuit (the fat red wire) not in the electrical system (the thin red wire).

You can have a badly corroded power cable, this can give the symptom you are describing. I assume that the battery connection itself is clean and has good integrity.

The battery starts the car. Once the engine is running, all electrical demands are met by the alternator. When the engine is running, the voltage on the positive terminal of the battery should be something close to 14.5v. You can test for 14.5v at the B-Post, if there is a deviation between here and the battery, then you have trouble with the cable that goes from the B Post to the battery. If there is not 14.5v at the back of the starter, then the alternator is not putting out enough power.

The alternator produces an AC voltage that is fed into a bridge rectifier (4 diodes arranges in a particular manner) that puts out a DC voltage. The rectifier circuit includes a pair of brushes that ride upon the commutator (main shaft) of the alternator. These brushes carry the power to the rectifier circuit, when is then connected to the alternator output -- the fat red wire.

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I just went back up to autozone with my New starter, and it tested just fine, they did give me a new battery, i just threw the multimeter on there and it was idling at about 12.2 volts? can this be a dme issue?


When running, the engine produces 14.4vDC. Period. If this is not what you have at the battery, then you have 1.) a bad connection somewhere, or 2.) a bad alternator, or 3.) a combination thereof.

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When the alternator does not work, the vehicle is driven entirely by the battery until such time as the battery dies.

There is a Charging System Light (looks like a battery symbol) that is REQUIRED to come on when the key is set to Position II (RUN), before Engine Start. If this light does not come on, the exciter circuit of the alternator will not work, the alternator will not produce the necessary voltage/current.

[JDStrickland]

stop posting on my posts unless you have some answers to the problems i post about! are you the post police?


I did post. Stop making double posts, it just makes your life worse than it already is.

For a guy that needs help, you resist the efforts far too much.

[mrowe87]

i saw your answer, thanks for the elaborate post, i appreciate that! im also a bit hypersensitive at the moment and I didnt see that you had actually given feedback on the other post, I just thought you were giving me a hard time, something I would prefer not to endure from a human at the moment as my car is doing a just fine job with that!


I did post. Stop making double posts, it just makes your life worse than it already is.

For a guy that needs help, you resist the efforts far too much.

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i did! i took my old one up to autozone, they said it was fine AFTER they had told me that it had a bad voltage regulator the day before. So I installed a new one, same problem. thats when i took my old one back up to auto zone, then reinstalled it, then took my newest alternator that wasnt fixing anything back up there this morning and they also told me it tested fine!


Varies from 12,2-12.8 sounds like a bad voltage regulator or bad alternator. Get it tested somewhere else.

[mrowe87]

how is it possible to check those points to see what voltage is being output? because I have to take off my air intake box and move several other things to get to those wires back there?

[JDStrickland]

You can check the B Post easily.

You can connect an alligator clip (test lead) to the starter, and again to the alternator.

You can run the car with the air box off, although this will likely trip a check engine light for the missing MAF sensor. You can reset the check engine light easily enough. I might not DROVE the car with the air box removed, but you can run the car for the purposes of testing. You can drive the car, but you will want to avoid dirty conditions. You can run the engine in your driveway without hurting anything.

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12.2 ~ 12.8 is not enough.

I missed the response to my question, does the charging system light (battery symbol) light when the key is set to Position II (RUN), before engine start? If no, then this is your trouble.

[jmo69]

it varies from like 12.2-12.8...... but when i turn my key it has dropped to 8 this one particular time I was looking at it.
Either your starter has a massive amperage draw or the battery doesn't have the reserve you need, either way your alternator should be putting out that 13.4v at idle. That current is going someplace, IIRC you said you checked for parasitic draw.

[spyderg0d]

Check your wires and terminals...

[mrowe87]

yea my battery light comes on

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is there any possibility these alternators could test good with a bad voltage regulator

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i jsut tested these posts you described with the car off at the alternator and started, and they are reading 12.8


You can check the B Post easily.

You can connect an alligator clip (test lead) to the starter, and again to the alternator.

You can run the car with the air box off, although this will likely trip a check engine light for the missing MAF sensor. You can reset the check engine light easily enough. I might not DROVE the car with the air box removed, but you can run the car for the purposes of testing. You can drive the car, but you will want to avoid dirty conditions. You can run the engine in your driveway without hurting anything.

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12.2 ~ 12.8 is not enough.

I missed the response to my question, does the charging system light (battery symbol) light when the key is set to Position II (RUN), before engine start? If no, then this is your trouble.

[spyderg0d]

Turn the car off and check every fuse for power drain. Whatever fuse has power still pull it if it shouldnt be on all the time.

[mrowe87]

i just took my intake box off and ran the multimeter to the terminal at the back of my alternator with it off, and then on, and it literally stayed the same, whats this an indication of? and autozone just told me this thing tested good?


Either your starter has a massive amperage draw or the battery doesn't have the reserve you need, either way your alternator should be putting out that 13.4v at idle. That current is going someplace, IIRC you said you checked for parasitic draw.

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i mean it does increase with being revved to like 13.5-.8 volts at about 2500 rpm

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i did check all my fuses for a parasitic draw already and theres nothing

[JDStrickland]

Turn the car off and check every fuse for power drain. Whatever fuse has power still pull it if it shouldnt be on all the time.


That's not the reported problem, I think.

He said that the car needs jumper cables to start, but only runs for a while and then dies. The car is running on the battery, and that's not the way it is supposed to be.

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yea my battery light comes on

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is there any possibility these alternators could test good with a bad voltage regulator

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i jsut tested these posts you described with the car off at the alternator and started, and they are reading 12.8



It should not be reading 12.8 when the engine is running. It should be 14.4. It can vary 0.1 on the + or - side, but still more than 12.8.

[spyderg0d]

Ya.. Got cha jd. Im thinking he has a short somewhere draining the power from after the alternator cuircuit. So the power is being sapped somewhere before it hits the battery.. Or.. Your connection to the battery is bad. Im fighting the same issue. My altinator puts out 13.8v but my battery only sees rouphly 13.3 of it and really doesnt do a good job of keeping it charged well at all.

[mgoods50]

I can't add a thing here except for maybe using another meter and seeing what that reads. Jd and Spyder have it covered. I'm lurking and thinking though, and waiting to see what happens.

I'll add that you might go to another parts store and see what they say upon checking. I don't particularly trust order takers and whats-on-sale-this-month promoters (no offense to any of them, they only have their limited training to go off of). It also depends on the equipment, what they are able to tell you.

Call ahead and see if places can check an anternator OFF the car. This is a different piece of equipment and more old school (reliable imho, maybe easier to interpret) than fancy load testers.

[shogun]

I now merged the 2 threads, so some info/posts might be double, but still better than 2 threads on the same subject.
Also deleted some posts with the discussion about the 2 threads, as these are not relevant to the technical problem.

[E36328Coupe]

If it was mine I would measure the voltage between the alternator output pin to both an earth on the car and alternator output pin to alternator body.

(If the alternator case is not earthed the alternator will not work (charge) )


But it's not mine so I recommend nothing

[spyderg0d]

Um.. I wonder if the alternator pully is slipping on the belt? Also check belt tensioner.

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Maybe spray some electrical cleaner into the altinator.

[mrowe87]

i checked my volts, even at the back of the starter and the alternator, its only about 12.6 volts with the car running, until acceleration happens, then it goes up! but its still no enough to maintain a charged battery!

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its spinning just fine, its a new alternator i dont want to spray anything in there, i do wanna figute this out tho

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yeah i took it to antother store, and its putting out 14.8 volts he said just fine, he also told me its a wiring issue somewhere, but I really dunno how to figure out the wiring gremlin, and I did have the alternator off and thats how it got tested, I was hoping he would tell me my new alternator sucked and I needed a new one but he said it was good! Theres a wiring issue, that just started this week somehow someway, and Im lost in this area



I can't add a thing here except for maybe using another meter and seeing what that reads. Jd and Spyder have it covered. I'm lurking and thinking though, and waiting to see what happens.

I'll add that you might go to another parts store and see what they say upon checking. I don't particularly trust order takers and whats-on-sale-this-month promoters (no offense to any of them, they only have their limited training to go off of). It also depends on the equipment, what they are able to tell you.

Call ahead and see if places can check an anternator OFF the car. This is a different piece of equipment and more old school (reliable imho, maybe easier to interpret) than fancy load testers.

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flyfishvt suggested this earlier and i did this, there was no change! and the alternator is working, when revved it puts out 13.5 or somehting volts but only like 12.4 at idle.


If it was mine I would measure the voltage between the alternator output pin to both an earth on the car and alternator output pin to alternator body.

(If the alternator case is not earthed the alternator will not work (charge) )


But it's not mine so I recommend nothing

[spyderg0d]

So.... Back to the drawing board.. Your altinator is capable of making appropriate voltage... But it doesnt on your car. Sounds like you have a short or a ground issue or a bad connection.. How hard is it to get. Check your freakin ground straps. The engine bay and the battery terminal. Check your circuits at the fuse box for exvessive draw. Make sure the fuses are appropriate sizes.

[E36328Coupe]

flyfishvt suggested this earlier and i did this, there was no change! and the alternator is working, when revved it puts out 13.5 or somehting volts but only like 12.4 at idle.He didn't suggest what I asked anywhere in this thread.
Just to be very clear you measured the voltage across the alternator output pin to the alternator case by putting once probe on the alternator output and the other on the cylindrical alternator body / case, and then from the alternator output pin to the car body or chassis - not elsewhere on the engine?

[mrowe87]

i checked the ground a while ago and its tight... did the fuse draw thing yesterday and theres nothing pulling crazy on my electrical system.


So.... Back to the drawing board.. Your altinator is capable of making appropriate voltage... But it doesnt on your car. Sounds like you have a short or a ground issue or a bad connection.. How hard is it to get. Check your freakin ground straps. The engine bay and the battery terminal. Check your circuits at the fuse box for exvessive draw. Make sure the fuses are appropriate sizes.

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no i didnt do what you described, i took a jumper cable and attached it to my alternator and attached it to the negative of my battery terminal


He didn't suggest what I asked anywhere in this thread.
Just to be very clear you measured the voltage across the alternator output pin to the alternator case by putting once probe on the alternator output and the other on the cylindrical alternator body / case, and then from the alternator output pin to the car body or chassis - not elsewhere on the engine?

[jmo69]

no i didnt do what you described, i took a jumper cable and attached it to my alternator and attached it to the negative of my battery terminal

I think he's trying to determine if the engine to chassis ground could be at fault. You might want to physically check it, right side near the motor mount.

[flyfishvt]

I think he's trying to determine if the engine to chassis ground could be at fault. You might want to physically check it, right side near the motor mount.

No I was not trying to test that. If that was faulty the engine would not crank. I was trying to determine if the alternator was properly grounded to the engine. Not all alternators are grounded to the engine but doe are. Installing a separate ground strap from the outer case directly to a chassis ground eliminates this possibility.

It's time to get this thing tested at a reputable shop.

[E36328Coupe]

No I was not trying to test that. If that was faulty the engine would not crank. I was trying to determine if the alternator was properly grounded to the engine. Not all alternators are grounded to the engine but doe are. Installing a separate ground strap from the outer case directly to a chassis ground eliminates this possibility.

It's time to get this thing tested at a reputable shop.
^^ Exactly.

People forget that alternators require both live and an earth to make power, they are not dynamos.

If the alternator is good you make sure it is earthed AND that all the other connections are OK because if only showing battery voltage on the output one of the pre-requisites has to be missing.

If it was mine I would dig out the multimeter, set it to OHMs and check the appropriate wires for continuity or resistance that could cause a voltage drop

[spyderg0d]

Un plug the posative terminal at the battery and at the post under the hood. Test at the end of the red cable to the frame or ground piont for continuity.

I bet your posative cable is shorting out on the frame at a worn spot on the cable. I think this is why my car also has this problem. No parasitic drain at fuse box. Altinator puts out 13.4 v at 600 rpm to the battery. Yet the battery is always drained after running. Car runs with battery unplugged. Pop starts. Jump starts. Its the only explanation.

[mrowe87]

so i dont know what the reason is, I suspect the rain did something to cause my electrical system to run poorly. As my car is no longer dying and running at higher voltage, its still not exceeding 13.7 volts even when revve, it idles and revs at 13.7, and my alternator tested at putting out 14.5 volts at the store. I dont know the cause behind this, but My car isnt dying anymore, so I suspect the rain as it was pouring for 3 days here in az when this little mishap started, thanks for the feedback everybody

[E36328Coupe]

You have had the battery off or disconnected to charge between it being as it was and now haven't you?

[mgoods50]

I'm going to assume there isn't some dumb underdrive pulley installed on the alternator .

If you have an original, OEM (factory, not autozone) alternator, physically measure the diameter of the pulley and compare it to what is on there now. That's the only thing that makes sense, if it puts out more on a bench test. Still doesn't address why volts aren't higher with revs . 2500 RPM should max the output (if it senses max output is needed) I'd ask whoever bench tested the alternator the RPM used, and the amperage output, as well as voltage .

Again, parts store people are order takers and promo of the month pushers. (And that's fine, no offense to anybody). They are not diagnostic experts by any stretch of the imagination typically. Im surprised they haven't suggested pouring a bottle of Lucas into the tank to fix it.

Also, these cars love to collect water in the plug wells. The seal on the engine cover shrinks, and let's water in. I can't tell you how many m/s5x engines I've seen with water stains on the boots. When water is present, it will ground out the spark and cause an occasional misfire. It seems to take forever to dry also.