charge trek VI - 'I'm losing my mind'

[tim eh?]

Tim... gotta stop this problem!

1. Belt tensioner fault. Not tight enough would cause problem.

2. Bad ground cable at the battery and starter.

3. Bad alternator... Eliminated

4. Bad battery... ELIMINATED

5. Bad starter...

6. Bad fusible link?...

7. Instrument cluster board prone to farting.

8. Previously installed alarm system (http://www.bimmernut.com/forum/showthread.php?p=306566#poststop)... 'fixed' but I still haven't ruled this out.
*- i think there are still some wires for this behind the stereo.

9. Engine electrical system?... brought this up once but nobody commented.
whacked ignition coil or something? I have no idea myself.

10. A/C system? ... can I defuse it?
This would be a good one... you know... i only just thought of this but there is a belt (that does work) on the a/c system (that doesn't work). i guess i might want to take that off. could that matter? also... isn't the aux fan supposed to turn on at a certain temperature? I can get it to run with direct current, I think the 2-temp switch is just fried.



Today - New Battery In. No change in symptoms whatsoever.

Tomorrow I will replace the battery to chassis and engine to chassis grounds (http://www.bimmernut.com/forum/attachment.php?attachmentid=6243&stc=1&d=1226255037), also the fusible link. Will check continuity from alternator casing to engine block. And I will throw in my spare white-backed cluster. Then I will check to see if it loses charge overnight, but I won't be confident of the readings for a couple of days. Guess I should redo wiring to starter... I haven't examined those really any tips? Are there kits or anything like that?

If bat is losing charge, I will suspect starter shorting out somewhere, and will install an inline fuse to see if it blows overnight.

starter is ugly (http://www.bimmernut.com/forum/attachment.php?attachmentid=6252&stc=1&d=1226413394), hmmmm i've replaced everything else... :(

Could somebody check my m20 alternator belt routing please? pic1 (http://www.bimmernut.com/forum/attachment.php?attachmentid=6259&stc=1&d=1226532361) pic2 (http://www.bimmernut.com/forum/attachment.php?attachmentid=6258&stc=1&d=1226532361) pic3 (http://www.bimmernut.com/forum/attachment.php?attachmentid=6257&stc=1&d=1226532363) If I routed that wrong I will be embarrassed but so very happy. It's tight, really... it's really tight... I have tried it at different tensions and it doesn't change anything.

The main clues are whether the battery still loses charge overnight and..
***When cold the system charges fine... great ... 14.0V+ with absolutely every button pressed that can be pressed.... for the first 2-3 minutes...
then it drops off a cliff to below 12.0V and stays there. (temp guage has moved +/- 1/10th of it's range) I really have to turn everything off then to get the voltage back up but then I can run a medium load (lights, no defrost, heat on 2, radio) ok.




Your ten minute trip with all your electrical loads would tax any charging system..its that simple .Get the best battery you can get that is the proper size.See if you get the 150 amp alternator too next time:D

+1

Your battery was on it's way out because it isn't getting a good enough charge. The voltage dropping like it is when you've got that many things electrical running is telling you that the alternator isn't putting out enough juice to run everything and charge the battery.

Wonder how complicated it is to retrofit the battery location to the trunk?

Guys I have considered this a lot and I really am not qualified to argue this point with anyone, but it doesn't make sense to me. My old (probably 20 years old) 115A alternator charged everything fine, I would have noticed - I didn't have a problem like this all winter and I was using all the power quite a bit. Anyone have an idea how many amps a fully loaded system would use? I'm guessing 20-30 amps? but I haven't a clue really. But I don't believe that the stock charging system would be designed to operate that close to capacity even with all the buttons pushed... but maybe I'm totally wrong about this. I'm thinking about wiring an ammeter into the circuit but you have to do that in series and I wonder if I'd have to reroute a whole pile of thick wires into the dash. (not interested...) But I think with 3 different alternators and 2 batteries, if the problem was there then there would have been some variation in the symptoms, and really it does the exact same thing every time.

There is a cd changer under the seat and often an entire string quartet in the trunk so it's a no-go as far as battery relocation, as much of a joy as that would be. And still, I think putting a giant battery would just alleviate the symptom not the problem. A stock car really ought to run ok on a brand new stock battery/alternator combo, seriously, it ought to power the rear window defroster, no?

Thanks tho, please argue the other way I really appreciate your opinions!




One cool thing about all this is that even though I have some experience with musical instruments, amps, computers- that kind of thing, I'm still pretty much all newbo and I have suspected all the wiring work I have done myself since getting the car, but so far all of it has turned out to be ok. (haven't gone behind the stereo yet) Still... right now the possessed car is winning...

[Claude]

[QUOTE=tim eh?
The main clues are whether the battery still loses charge overnight and..
***When cold the system charges fine... great ... 14.0V+ with absolutely every button pressed that can be pressed.... for the first 2-3 minutes...
then it drops off a cliff to below 12.0V and stays there. (temp guage has moved +/- 1/10th of it's range) I really have to turn everything off then to get the voltage back up but then I can run a medium load (lights, no defrost, heat on 2, radio) ok.
QUOTE]

Tim you summerized the essential here. I think that we may now trust both your new battery and alternator and you're right they should easily do the job properly.

Normaly such voltage drop could be signs of either bad cell within the battery (excluded now) or bad intermittent alternator voltage regulator (exclude too now). I would say that this major voltage drop (from 14 to 12 volts) is due to a heavy / abnormal load that suddenly appears from where ?? that's the question ! Or bad grounding (intermittent) in between negative battery pole and the alternator.

The starter connections does not look good at all, but your starter does it's job OK and is out of the circuit (received no current) when the car is running, i would forget about it.

Your A/C compressor has a electrical clutch that does'nt seems to engage, chances are that's because your A/C has loose it's gas in such a case a protection system / switch enable the compressor to operate (compressor protection), so the problem is not there.

Good idea to read the total load the battery have to drain when the car is running, so equiped you'll be able to see if it's really and extra load that the battery has to take after 2-3 min of normal operation (if not, it's only a volatge drop so the grounding system could be the culprit). But to do so easily that's a clamp on current meter that you would need.

Don't give up !

[bad_manners_god]

I may be way off here tim, but clean your ICV, Idle control valve.

Reason: The ICV compensates for accesories, power steering, ac and anything else electrical by increasing the idle thus charging the alternator.

Also, 2 weeks ago I was working on my friends turbo neon and we've installed Megaquirt ECU into it and took away the spark and fuel control from the stock pcm and we left the IAC (Idle Air Control) to control the idle except because the stock pcm lost alot of it's inputs the IAC was going nuts, opening from 1200 to 2100 to compensate for nothing.

Solution: Unplugged the IAC, turned on all accesories in the car and adjusted the idle with the stop screw on the Throttle Body. Idles at 1100 perfectly now.

I'll keep thinking.

EDIT: Maybe test 9 on the OBC gives false readings after 2-3 min of operation, have you confirmed with a Multimeter when the Voltage drops?

EDIT 2: Maybe this will help:

http://i252.photobucket.com/albums/hh25/badmannersgod/ScreenHunter_03Nov130017.gif

http://i252.photobucket.com/albums/hh25/badmannersgod/ScreenHunter_02Nov130007.gif

http://i252.photobucket.com/albums/hh25/badmannersgod/ScreenHunter_01Nov130005.gif

[bmwrp8]

unhook connector from alarm module, check wiring that goes to alternator. see what happens:) or if your car has wiper pressure adjuster ( sorry don't really know whats it called) if its grounded or busted it draws power from the batt.even when off.. just disconnect the system but i guess not all e34's has it i guess only e32's but if you have, it might be the culprit. http://bmwe32.masscom.net/dutch740/wipertensioner.htm

[sal_park]

ok, been thinking about this.

As suggested above *something* happens at 2-3 minutes in which causes low voltage. What about this for a possibility:

1) The car has been sitting overnight, and is stone cold.
2) Obi-Wan ( :) ) starts the car.
3)The car does lots of stuff to keep the engine running smoothly during the warm up phase - raises the idle, uses extra fuel etc etc. End result is the idle is smooth and throttle response predicable because the idle has been raised by say +300 rpm above normal idle.
4) At somepoint later in the warm up phase (say 2-3 mins), the senors say, ok the engine is now warm, we can drop the idle back to normal, and so it goes back to the normal of say (guess) 800 rpm.

Could it be this is the point the system voltage goes from 14v -> 12v ? What I'm thinking is the alternator is turning off because the the engine is idling too low.

AFAIK, with all cars the alternator will only start to work above a given engine speed. If the engine ever drops below that speed (say for example 500 rpm) the alternator will cut out and only turn on again once the engine speed increases past the minimum. Obviously the alternator light *should* come on if this happens, but given the instrunment display is a little doddgy, what's to say the sensor light for the alternator light is operating correctly ?


I would suggest that:
< 12.5v is not charging
> 12.5v is charging

Tim, can you try the following:

1) get the car in a state so it will be showing a system voltage of ~12v when running (i.e. bad).
2) play with the throttle to try and see if there is a particular rpm that the system voltage jumps to ~14v, bearing in mind that the engine speed on the way up may be quite different from the engine speed on the way down, so it could be: not charging 800rpm, (increase revs) starts to charge 1200rpm (decrease revs) stops charging 1000 rpm.

What speed does it idle at when warm?

Is it an auto ? If so , what speed does idle at when warm in N and in D ?

Perhaps bad_manners_god has hit the nail on the head suggesting looking at the ISV ?

sal

[Ferret]

There's something very wrong here... what speed does your car tick over at?

Sal I think has a good idea, if you rev the car the voltage should jump up at some point. If it doesnt, the only thing I can think of any more is that all three alternators you've had have had the same batch of replacement regulators in them... meaning all three alts were bad.

The only other thing that would cause it to stop charging like that is a dip in RPM combined with a bad supply voltage on the field coil terminal.

Do the following tests:
Set your meter to volts, and clip one lead to the battery positive terminal, and the other to the B+ post on the alternator, run the car and see if anything shows up. In all states, IE first start while it's charging, when the charge drops off and while you're revving the nuts off the car.
Do the same test again, but measure the voltage between the alternator casing and the battery negative terminal.

If you get a voltage doing either of these tests, there's a high resistance somewhere...

[Tiger]

No... not plausible. What is plausible is the belt is not tight enough that the alternator slips... and thus reduce the voltage.

[sal_park]

No... not plausible.

Which bit ?

[sal_park]

as regards the tension in the alternator belt, I would expect that you should be able to push/pull the belt about 5/8 inch up/down when holding it in the centre of the longest span between 2 pulleys.

[Ferret]

No... not plausible. What is plausible is the belt is not tight enough that the alternator slips... and thus reduce the voltage.

My V8 does it... at idle with full load it'll only produce 12.something, give it a few beans and it'll perk right back up to the 14 ish mark. Belt's not slipping either.

[Tiger]

Mine is 14 at idle.

[Tiger]

Tim, I cracked the Bentley Manual for you. Here is some test I want you to do.

At Alternator.... with ignition key on...

Check battery voltage between ground and terminal B+... same for the D+

[Bill R.]

at 1500 rpm, you can't go by the idle output.

[Tiger]

Hi BillR... The alternator needs feedback from the D+ wire in order to determine what charge he need... The voltage regulator needs this information to determine how much volage the system needs.

Bentley manual said with everything off and door closed or the door lights off, up to 100mA is acceptable. But I think his problem is charging system.


Any charging system should at least put out 13.5V at idle or otherwise it will drain the battery. Bentley also said to make sure the battery cables has good clean contacts... not only at the battery but where the battery cable... such as ground goes to the chassis.

A crude load test technique outlined in Bentley is with engine running, at 2000 RPM... turn on fans, lights, rear window defroster and wipers... the voltage should at least be 12.0V.

We need to eliminate Tim's problem... he is running all over places and confusing everyone.

[Tiger]

Good tuitorial on alternator for Tim is here...

http://www.familycar.com/Classroom/charging.htm

Right now I am suspecting the D+ wire... Tim, does your charging light work when you turn it on without starting the car?

[tim eh?]

... fusible link.

http://www.bimmernut.com/forum/attachment.php?attachmentid=6260&stc=1&d=1226604570


not 100% sure but i'm taking bets against it.

won't know until i can start the car again :D


do i have to solder it? wire is still good i can just clamp another one on no?


it's too bad - i went out and did i pile of multimeter tests and have some good pics... maybe i'll post them in a 'charging system for dummies' thread.

http://www.bimmernut.com/forum/attachment.php?attachmentid=6261&stc=1&d=1226604570



I really can't tell you how much I appreciate the help, guys... I thought I was gonna lose it!

[sal_park]

1) get the car in a state so it will be showing a system voltage of ~12v when running (i.e. bad).
2) play with the throttle to try and see if there is a particular rpm that the system voltage jumps to ~14v, bearing in mind that the engine speed on the way up may be quite different from the engine speed on the way down, so it could be: not charging 800rpm, (increase revs) starts to charge 1200rpm (decrease revs) stops charging 1000 rpm.

How did you get on with these tests ?

[Tiger]

Read this link...

http://www.familycar.com/Classroom/charging.htm

[bad_manners_god]

Read this link...

http://www.familycar.com/Classroom/charging.htm

Defiently worth a read.



AFAIK, with all cars the alternator will only start to work above a given engine speed. If the engine ever drops below that speed (say for example 500 rpm) the alternator will cut out and only turn on again once the engine speed increases past the minimum. Obviously the alternator light *should* come on if this happens, but given the instrunment display is a little doddgy, what's to say the sensor light for the alternator light is operating correctly ?

Sal: An Alternator is not like a A/C Compressor which uses a clutch to engage it. The Alternator Rotor is always turning producing some sort of charging, even if it's small amount. What your describing is the Voltage Regulator, which if faulty wouldn't allow enough current to pass back in the car's electrical system.

This could also explain why the car works fine for 2-3 min, before the Regulator heats up and starts to fault.


Tim, you can just crimp it on, solder would be a nice touch, make sure you use a link with the right rating otherwise you'll have more problems.

[tim eh?]

i think the po straightpiped it (....man!)

it's hard to find ring terminals for 6 gauge wire. (here, anyway) went (walked) to 4 places.

there is still time for bets... i'll take the demonspawn for a spin just as soon as the pizza gets here.

http://www.bimmernut.com/forum/attachment.php?attachmentid=6265&stc=1&d=1226622310http://www.bimmernut.com/forum/attachment.php?attachmentid=6266&stc=1&d=1226622310

http://www.bimmernut.com/forum/attachment.php?attachmentid=6267&stc=1&d=1226622310

*- pics fixed (..?)

[bad_manners_god]

i think the po straightpiped it (....man!)

it's hard to find ring terminals for 6 gauge wire. (here, anyway) went (walked) to 4 places.

there is still time for bets... i'll take the demonspawn for a spin just as soon as the pizza gets here.

http://www.bimmernut.com/forum/attachment.php?attachmentid=6264&stc=1&d=1226619452http://www.bimmernut.com/forum/attachment.php?attachmentid=6263&stc=1&d=1226619452

http://www.bimmernut.com/forum/attachment.php?attachmentid=6262&stc=1&d=1226619452

pics not working

[Tiger]

Car stereo shops has those rings for thick gauge wires...

[tim eh?]

there is a slight improvement, tho the cliffdropping voltage is still there.

it was really ugly, there was a very suspicious wire parallel with the fuse, which I think was already busted.
There's another one somewhere in the car I think I should look for.

I did all those tests I think...

Alternator to ground (chassis) (ignition key on)
B+ = 12.2V
D+ = 1.47V
D+ = 48.4ohm

HMMMMMMM!


The car kinda went nuts when I tried to measure voltage between bat+ and the B+ alternator post. Revved to 2000 by itself, then kind of all over the place, then I stopped.

The rest I'll have to post later... believe it or not I actually have a job! :D

I had to abort the testing and replace the fusible link after I broke it. All i did was give it a good wiggle and everything was dead after.

650 rpm at warm idle? something like that... 750 when cold... very very steady, it runs really really well.

oh and i pulled the fuse for the headlight washing system, which uses the same 30A fuse that the wiper pressure system would use if i had it but no change... i think tiger's narrowing in on this, still i think overall the entire electrical system could use an overhaul...

edit- couple things

the charge light works as bentley says it should
the belt is tight it's really frikkin tight!

[632 Regal]

Got to be getting closer now.




Alternator to ground (chassis) (ignition key on)
B+ = 12.2V
D+ = 1.47V
D+ = 48.4ohm


The car kinda went nuts when I tried to measure voltage between bat+ and the B+ alternator post. Revved to 2000 by itself, then kind of all over the place, then I stopped.

[Tiger]

D+ should be battery voltage... that is your problem.

You said you were messing around with instrument cluster? Did the charging problem happen after you worked on instrument cluster? You need to check if the D+ wire is damaged... trace it back as much as you can to find the problem.

Your battery is draining because it is not charging up your battery.

[632 Regal]

Exactly what I thought but you guys are better at this than me, that 1.47 was just wrong in my head. With his weather all the condensation and humidity (and rain) could it be the connection at the alternator? And is there any other connection areas besides back under the dash?

Edit: I really need another controversial sig pic.


D+ should be battery voltage... that is your problem.

[Ferret]

Exactly what I thought but you guys are better at this than me, that 1.47 was just wrong in my head. With his weather all the condensation and humidity (and rain) could it be the connection at the alternator? And is there any other connection areas besides back under the dash?

Edit: I really need another controversial sig pic.

I agree with these guys, you've found the problem at last I think... while I'm working on mine today I'll try and get a reading off the D+ terminal to see what it should be... the car'll be up in the air anyway while I pull a broken spring off it >: ( (with the amount of road tax we pay, I'm getting fed up with all the pot holes in our roads)

If you cant find the bad connection a quick solution to this is to just take an ignition feed from somewhere and rig up a dash style bulb and a new line to this terminal...

[tim eh?]

D+ should be battery voltage... that is your problem.

You said you were messing around with instrument cluster? Did the charging problem happen after you worked on instrument cluster? You need to check if the D+ wire is damaged... trace it back as much as you can to find the problem.

Your battery is draining because it is not charging up your battery.

TIGER _ please don't ever leave this board!!!!!!!

thanks++++ everyone! (tho it's not over yet)

you know what, I actually did those tests in the bentley when this first happened ... man, i feel dumb... i remember getting that voltage reading and thinking it was iffy.

the connector at the end of the wire going to the D+ was in rough shape so i spliced a new one in there, got exactly the same readings and kind of forgot about it.

looking at the wiring chart, it looks difficult to trace.... i'm on it tho! when the first alt died, the abs light would flicker, but it hasn't since (it works). i have taken the clusterboard out a few times but not recently iirc. could it still be the cluster itself? i will swap the other one in...

TBC! ... (kirk out...)

[Ross]

Tim,
I've been out of commision for a couple days. I'll be beaming that cluster up post haste.
Scottie

[tim eh?]

Tim,
I've been out of commision for a couple days. I'll be beaming that cluster up post haste.
Scottie

hope your dentist didn't slip or anything... no rush on the cluster, i have to wait for an unloader relay too....

(see episode VII (http://www.bimmernut.com/forum/showthread.php?t=39885))