charging woes partII

[tim eh?]

i'm going nuts help me please

There is a big background to this but the thread is long and full of stuff that doesn't matter anymore (http://www.bimmernut.com/forum/showthread.php?t=39752),
I think all the relevant stuff is here.

I am using the obc test#9 for these tests... I compared it at idle to readings with the voltmeter and it seems to be pretty reliable.

The system runs at 14.2V at idle when cold with nothing on.
.... >13.4V at idle when cold with everything* on.
.... <12.0V at idle when warm with everything* on.

*highbeams, stereo, blower, rear defrost it's all i've got! The rear defrost really kills it.

Battery is new December/07 - it passed a load test at the shop yesterday.

Battery is at 12.50V after driving, 12.62V if I remove the neg terminal.
No change to this if i disconnect the main terminal at the alternator.

Goes to around 12.15V the next morning.

Using a new multimeter I got the DCamp test working... (http://www.bimmernut.com/forum/attachment.php?attachmentid=6226&stc=1&d=1225924491) but the static draw test (http://www.bimmernut.com/forum/attachment.php?attachmentid=6187&stc=1&d=1225924764) blows the 315mA fuse every time (even with alternator disconnected).
What's with the 10A setting? That looks scary but I'm so tempted.

I replaced the original alternator (which just crapped out... the symptoms weren't the same) with a rebuilt (not bosch) one during the summer. I didn't notice these problems until recently but they might have been happening since i replaced it. When i first noticed this I thought it was the alternator and took it back but I get the same symptoms with a different (still not bosch) one. The belt is brand new it's tight I'm pretty sure, I've checked it plenty.

So I guess there is a definite >315mA drain somewhere. But if it's just an accessory could it be enough of a load to kill the system voltage like it does?
And why oh why does it only do it when the engine is warm???

Can a faulty alternator drain a battery like that just sitting there?

I have removed the main terminal from the alternator and will test the battery voltage tomorrow morning (will suck in the dark) , will that tell me anything(?) or should I do something useful, like start pulling fuses.

The parts store will send it in for testing if i take it to them should I just do that?

help meeeeee!

[Claude]

Q1:The system runs at 14.2V at idle when cold with nothing on.
.... >13.4V at idle when cold with everything* on.
.... <12.0V at idle when warm with everything* on.


Q2: So I guess there is a definite >315mA drain somewhere. But if it's just an accessory could it be enough of a load to kill the system voltage like it does?
And why oh why does it only do it when the engine is warm???

Q3: Can a faulty alternator drain a battery like that just sitting there?

Q4: I have removed the main terminal from the alternator and will test the battery voltage tomorrow morning (will suck in the dark) , will that tell me anything(?) or should I do something useful, like start pulling fuses.

--------------- ----------
E1: 12 v at idle warm or cold not normal (should stay 13.5 v and a up) bad battery or bad alternator. But you say battery load test passed OK, so suspect the alternator.

E2: 315 ma drain is not very high, should'nt be the cause of voltage drop you report, but such a drain is not normal (should be lower) otherwise if the car stay unused 2-3 days that drain is enough to drain the battery flat

E3: Yes a bad alternator (shot inside diodes in the regulator) may drain a battery

E4: Very good idea to isolate the alternator from the battery to night to see if it's the alternator itself that drain the battery... can't wait to see the result.

[Ross]

Start pulling fuses Tim. It's not the alternator, two in a row?
Wait a while to watch the draw, it takes time for everything to go sleepy.

[tim eh?]

thanks++++ guys




E4: Very good idea to isolate the alternator from the battery to night to see if it's the alternator itself that drain the battery... can't wait to see the result.

kinda dumb i only disconnected the main terminal should i disconnect also the small alt terminal also (i didn't :() or does it matter?


Start pulling fuses Tim. It's not the alternator, two in a row?

that's what i thought but it's weird i was pretty sure i had my wiring figured out. everything i mean everything electrical works perfectly except the a/c and the fog light cluster light (it's not the bulb and the foglights work... weird)



Wait a while to watch the draw, it takes time for everything to go sleepy.
I don't understand... you mean disconnect battery->wait->test or wait->disconnect battery->test.

i would get split second readings for a draw but then the fuse would blow.

with alternator connected 70mA
with alternator main terminal disconnected 20mA ...
i dunno if it was just the wire melting or what...

yeah... fuses are next... starting with IHKR i think - what a pain one test/night!

[bubba966]

So your electrical system is pulling over 315mA, blowing the fuse in your DMM when doing a load test with the car off?

Car should draw under 50mA when everything is off. Need to find out what's causing the power draw by pulling fuses 'till you get normal readings. Set your DMM to a higher range so that you don't blow more fuses in it while doing this.

[tim eh?]

So your electrical system is pulling over 315mA, blowing the fuse in your DMM when doing a load test with the car off?

yes the fuse blows every time after about half a second, but it does flash those readings.

the max setting with the 315mA fuse is 200mA. there is no higher one maybe i shouldn't buy these at the dollar store... maybe i could use the 10A unfused setting. I only kind of half know what I'm doing so 'unfused' is enough to put me right off, whether it's me or the car I'm going to hurt I just don't like the 'unfused' idea...

I want to rule out the alternator first because if it turns out to be suspect I don't have to piss around with fuses and finding a decent DMM.
Ughhh I hope winter comes late this year...

[Scott C]

yes the fuse blows every time after about half a second, but it does flash those readings.

the max setting with the 315mA fuse is 200mA. there is no higher one maybe i shouldn't buy these at the dollar store... maybe i could use the 10A unfused setting. I only kind of half know what I'm doing so 'unfused' is enough to put me right off, whether it's me or the car I'm going to hurt I just don't like the 'unfused' idea...

I want to rule out the alternator first because if it turns out to be suspect I don't have to piss around with fuses and finding a decent DMM.
Ughhh I hope winter comes late this year...

You can always put an inline 5a fuse in series with your leads to protect your DMM

[tim eh?]

You can always put an inline 5a fuse in series with your leads to protect your DMM

:D i'm mostly worried about frying a circuit board in the car i don't care about the DMM and i don't think i can start any fires unless i really do things backwards but yeah i should just do that - thanks.

as far as the possibility of getting 2 bad alternators in a row goes... actually where i live that's not so improbable now that i think about it.... sometimes you're lucky to actually get the correct part even. PITA shopping here sometimes.
(eg i went to 4 stores today before I found 315mA fuses - i found them at a place where the guy told me they didn't have any)

[bad_manners_god]

:D i'm mostly worried about frying a circuit board in the car i don't care about the DMM and i don't think i can start any fires unless i really do things backwards but yeah i should just do that - thanks.

as far as the possibility of getting 2 bad alternators in a row goes... actually where i live that's not so improbable now that i think about it.... sometimes you're lucky to actually get the correct part even. PITA shopping here sometimes.
(eg i went to 4 stores today before I found 315mA fuses - i found them at a place where the guy told me they didn't have any)

You got 2 bad alternators tim, I'm 95% sure, IT'S A VERY COMMON PROBLEM HERE, we get alternators and starters at the garage that are rebuilt and are deffective.

Just return it and say it's deffective and get another one.

[Ferret]

Time to wade into this one I think...

Your multimeter can wage war on upto 10 amps, if you plug the black lead into the common/ground normal port, and the red lead into the socket that's labelled 10A (it's usually marked with small lettering) set the meter to 10A and you can get a decent reading.

Your car shouldnt be drawing a current of 2-300mA when stationary and everything's switched off. You've got a current drain somewhere that's abnormal.

With regards to the rear defrost causing the voltage to drop down to 12v, mine does this as well - I've never really been arsed eyeing up the alternator and trying to figure out if it's natural.

You need to wire up your meter in it's 10A configuration, and start pulling fuses until you figure out what's drawing the current when the drain suddenly drops off.

Dont forget the fuses under the rear seat either, they've got a lot of ancilliary crap running off them - drain could easily be in one of these.

If after you've pulled all your fuses you've still got a drain, then you've confirmed it's an alternator or starter fault. They're the only two systems that should be left connected. (Though, there's some fuses in the e-box which you may need to pop out first.)

Another thought that's just hit - you've not any 3rd party audio kit fitted like amps etc have you?

[tim eh?]

Time to wade into this one I think...


Thanks very much Ferret... was just doing a lot of this just now, I'm getting better at the multimeter. Actually I have two now... one works well, the other doesn't work on the 10A setting (errr... is there an embarrassed smilie?) but it still comes in handy...

I do have an aftermarket stereo head unit and cd changer but nothing crazy and it never gave me trouble in my old car, also it worked fine with the old alternator.

The reason why the fuse kept blowing on the meter is because something resets itself every time i connect it so there is a surge of about 2A it looks like upon contact with the terminals with the 10A tester (normal i hope?). After that drops (takes a second or so) I can connect the <315mA tester, then remove the 10A tester and get a decent reading.

The overnight voltage drop was still there but keep in mind the little terminal was still connected... sure did suck doing that at 4am this morning with a flashlight.... got covered in rustproofing again oh god i hate that stuff.

here's what i got today on the draw test today...

everything connected ... 500mA
...glovebox closed (d'oh!) ...150mA

main terminal on alternator removed... 150mA
small terminal on alternator removed... 20mA

aha!

so i reconnected the alternator... 20mA wtf?

so that's all i had time for if i wanted to get it tested today, so i took it out and told the guy to make sure he let it heat up for a while before he tested it... hope to get it back today.

i'm guessing the alternator develops a short when it warms up which goes away if it's disconnected for a bit... definitely a guess....

so... assuming it's the alt, do i piss around with another a/m alternator or do i tell these guys to stuff it and go to someone who sells bosch? - quite a price difference... paid around $270 for this one (...these ones i mean) IIRC bosch would set me back around $450 i think.

bmg- when you finally get a good one does it STAY good???

in hindsight guess i should have changed the regulator and brushes on the old (bosch :() one but it really crapped out 100% and it was very old and covered in road ick.

noob question #godonlyknows... can i put a hella/bosch regulator/brushes on an aftermarket alternator?


*-oh yeah, almost forgot.. when i reconnected the battery after removing the alternator the craziest thing happened, I think it's just a freak thing and not related though. The locks just kept opening and closing like they were possessed, up/down/up/down really fast. I looked at all of them they weren't stuck or anything just locking and unlocking perfectly in sync. I didn't want to jam anything so I disconnected the battery, trying to time it with them being open but i timed it badly and they stopped on 'locked'. I was worried b/c I have never been able to use the manual unlock on these doors (managed it on my old original doors). Anyway, when i reconnected the battery they stayed locked but thankfully the key worked.... freaked me out! I think my car is possessed... it eats alternators...
then it laughs at me...

[tim eh?]

damn

tests come back all good

for now i can drive the car as far as the battery will take me, I'm supposed to call back tomorrow and maybe get the same alternator back. they're in walking distance at least... how much fun do y'all think I'm having?

maybe the charge light wire could be shorting against something... (?)

... fusible link? no way right?


*- as far as the battery goes... took it to my regular indie and hooked it up to the big yellow machine - i don't know what they jack out of it but it stayed above 11v and he said it could only be bad if it went near 10.5v or so... so battery? no way right?

[bad_manners_god]

It's a defective alternator...believe me now?

[Ferret]

Hmm, bmg may be right here, but there's something bugging me.

The initialise/field line (the small alt wire) should NOT be live while the car's shut off, hence it shouldnt be able to leak current.

With everything off, unplug the small alternator connector and measure the voltage on it, relative to ground/bodywork/engine block. Your alternator warning lamp does light up when you have the key in pos2 with the engine not running doesnt it? (It shouldnt while the alternator is out of the car!)

Send it back and get a replacement under warantee, it cant do any harm!

[tim eh?]

bmg i totally believe you, it's just it's the second one i've sent back and they are telling me it's ok. (i still believe you, i have to convince them)


Hmm, bmg may be right here, but there's something bugging me.

The initialise/field line (the small alt wire) should NOT be live while the car's shut off, hence it shouldnt be able to leak current.

With everything off, unplug the small alternator connector and measure the voltage on it, relative to ground/bodywork/engine block. Your alternator warning lamp does light up when you have the key in pos2 with the engine not running doesnt it? (It shouldnt while the alternator is out of the car!)

Send it back and get a replacement under warantee, it cant do any harm!

There was no overnight voltage drop with the alternator out (battery terminals connected).

20mA draw this morning (alternator still out).

I measured voltage at the alternator leads to ground. (alternator still out)
- main lead reads same as battery
- small lead reads zero

The warning lamp was functioning with the alternator in. (on in pos2 pre-ignition otherwise off) With the alternator out the lamp does not funtion.

How do I test that there are no shorts in those circuits... i think i just okayed the main circuit but how do i check for problems in the small wire?

I guess I'll try and talk them into giving me another one, man this is soooo brutal but I'm happy to have discovered the problem sooner rather than later (http://www.bimmernut.com/forum/picture.php?albumid=7&pictureid=73). The guy at the parts store tells me his guy says it's ok and I'm going to talk to them both today... I guess I just tell them everything...

fusible link... no way right? no way it gets hot and then restricts current? i guess that doesn't explain the battery drain...

[Ferret]

bmg i totally believe you, it's just it's the second one i've sent back and they are telling me it's ok. (i still believe you, i have to convince them)



There was no overnight voltage drop with the alternator out (battery terminals connected).

20mA draw this morning (alternator still out).

I measured voltage at the alternator leads to ground. (alternator still out)
- main lead reads same as battery
- small lead reads zero

The warning lamp was functioning with the alternator in. (on in pos2 pre-ignition otherwise off) With the alternator out the lamp does not funtion.

How do I test that there are no shorts in those circuits... i think i just okayed the main circuit but how do i check for problems in the small wire?

I guess I'll try and talk them into giving me another one, man this is soooo brutal but I'm happy to have discovered the problem sooner rather than later (http://www.bimmernut.com/forum/picture.php?albumid=7&pictureid=73). The guy at the parts store tells me his guy says it's ok and I'm going to talk to them both today... I guess I just tell them everything...

fusible link... no way right? no way it gets hot and then restricts current? i guess that doesn't explain the battery drain...

Before you return it, just do me one favour....

Switch everything off in the car, pull the small wire off the back of the alternator and measure to see if there's any voltage from it to ground there. It's still nagging at me that your fault may be voltage leaking onto this line from somewhere - at which point it would be natural for your alternator to sink the current.

EDIT: Just spotted that you already have. Your alternator's totally shot, backwards leaking current.

[Tiger]

Who did you buy the alternator from?

[Ross]

The locks jumping around tells me you have a problem there. maybe an actuator failing. Naw not on one of these cars.

[tim eh?]

thanks ferret


Who did you buy the alternator from?

bought it at 'Pieces St-Henri', it's a 'DNS 2000' this is the sheet that came with it. (http://www.bimmernut.com/forum/attachment.php?attachmentid=6229&stc=1&d=1226072563)


The locks jumping around tells me you have a problem there. maybe an actuator failing. Naw not on one of these cars.
no, i think it's possessed.

[Tiger]

Take it to autozone and similar... have them tested there.

[tim eh?]

Take it to autozone and similar... have them tested there.

Thanks - there is a place not far I think I can take it to, I don't think we have autozone, but if they give me the same one back I will definitely take it somewhere. The thing is... i think it only goes bad after it's been heated somewhat, so do i ask them to put a blowdryer on it or something?