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Discussion Starter · #1 · (Edited)
Background: One day in December 2008 after warming up my car I pulled out my driveway and immediately my cars dashboard gave me SES, AIRBAG, BRAKE, CONVERTIBLE TOP MAL, ABS, and a whole Christmas tree of lights i dont remember all of them. But anyways turned off my car to see if that would solve the problem and when trying to start it up again, it just cranked but wouldnt start. So then i got the battery change by Tischer BMW in Feb 2009, everything seemed to be going well after that, i drove it normally, no problems. Then in Dec 2009 same sh*t happened again where my car gave me those sh*t dashboard lights. I then turned off the car and after an hour, it started back it fine. I thought everything was solved but then after trying to drive it 100 feet, the lights come back.

Currently: I charged the battery at Autozone, they said it was a good battery when they tested it. Then i tested it myself and it gives me a reading of 12.33 volts. When i start the car and turn on the Xenon headlights and heater to 91 degrees full blast, the voltage reads 13.8 to 13.86 volts. So is my alternator bad... what else could it be if the problem is not the alternator????????

PLEASE HELP!!!!!!!
 

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First of all, did you have the battery load tested or did you just check the voltage? When a battery starts failing it may show a good voltage at low loads, you need to take it to the shop so they can perform a proper load test.

Regardless I'd highly recommend taking it to the shop and having the entire charging system checked. It's a system. Replacing one failing electrical component is rarely good enough, as one failed component will usually toast other components. If the regulator is bad it can toast the alternator and battery, so if you just replace the battery it will fail again. :facepalm: If you then replace the battery (again) and the alternator, they will both fail AGAIN. :facepalm: :facepalm: It's very costly to fix the charging system piecemeal. You need to have the entire system tested and then replace ALL the failing components.

Now I'm speaking about cars in general based on 10 years working for an parts/service center. Maybe someone else here can speak more specifically about BMWs and the E46. I still haven't got a code reader so I'm not familiar with the extent of the BMW diagnostics, which look really extensive. Anyone? :help:

good luck, I hate electrical problems.
 

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this may be signs of a slowly failing alternator...when you get undervoltage from the alternator, you will get most of the lights on the dash on because everything in the car isn't getting 12v like it should. Its really hard to diagnose something through the forum...but if you can get the lights to come on with the car running, see if you can get the voltage then and see what it is. When you say it wouldn't start, was it weak? like cranking slowly?
 

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Alternator

Bump, any ideas?
Well, here is my two cents. I just went thru this, and considered the Alternator route. I had no alternator bearing noise, and in my case, under high acceleration on the freeway, periodically, my dash battery light would go out, telling me the system was partially charging under these conditions. I have the Valeo alt and I removed the regulator while the alternator was in the car. I found a lot of carbon dust, and extremely low brushes. I cleaned the regulator out, got some brushes and installed them. then I cleaned the contact area for the brushes and reinstalled the regulator. It takes about 10 minutes to get the regulator out and it hardly cost anything. The car is up and running and Mom is happy. good luck
 

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First of all, did you have the battery load tested or did you just check the voltage? When a battery starts failing it may show a good voltage at low loads, you need to take it to the shop so they can perform a proper load test.

Regardless I'd highly recommend taking it to the shop and having the entire charging system checked. It's a system. Replacing one failing electrical component is rarely good enough, as one failed component will usually toast other components. If the regulator is bad it can toast the alternator and battery, so if you just replace the battery it will fail again. :facepalm: If you then replace the battery (again) and the alternator, they will both fail AGAIN. :facepalm: :facepalm: It's very costly to fix the charging system piecemeal. You need to have the entire system tested and then replace ALL the failing components.

Now I'm speaking about cars in general based on 10 years working for an parts/service center. Maybe someone else here can speak more specifically about BMWs and the E46. I still haven't got a code reader so I'm not familiar with the extent of the BMW diagnostics, which look really extensive. Anyone? :help:

good luck, I hate electrical problems.
Very good write up. bump
 

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Some good information here. I recently had the same "lit up dashboard" problem. My error code reader signalled a p0606 error -which i believe could be due to interruption of elctrical supply to the ECU. On testing my battery strength without starting the car, i get 11.5 volts. This is surely too low even without load testing?
 

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Background: One day in December 2008 after warming up my car I pulled out my driveway and immediately my cars dashboard gave me SES, AIRBAG, BRAKE, CONVERTIBLE TOP MAL, ABS, and a whole Christmas tree of lights i dont remember all of them. But anyways turned off my car to see if that would solve the problem and when trying to start it up again, it just cranked but wouldnt start. So then i got the battery change by Tischer BMW in Feb 2009, everything seemed to be going well after that, i drove it normally, no problems. Then in Dec 2009 same sh*t happened again where my car gave me those sh*t dashboard lights. I then turned off the car and after an hour, it started back it fine. I thought everything was solved but then after trying to drive it 100 feet, the lights come back.

Currently: I charged the battery at Autozone, they said it was a good battery when they tested it. Then i tested it myself and it gives me a reading of 12.33 volts. When i start the car and turn on the Xenon headlights and heater to 91 degrees full blast, the voltage reads 13.8 to 13.86 volts. So is my alternator bad... what else could it be if the problem is not the alternator????????

PLEASE HELP!!!!!!!
Jone or Perry or both,

Mileage? Year? Sorry if I missed that.

Aftermarket things?

What other elect. work might have been done incidental to original problems?

I like the cleaning and replacing brushs, regulator, but haven't done this myself. Had alt out...should've stepped up my diying! Anyone with link or 'crib' notes on this...Mr. Juan? Alt in, think you said for both brushes and reg, right?

Anyway, OP...Don't forget the basics too that many skim over too quickly in diagnosing elect. issues...

Battery cables tight? With replacement bats. sometimes terminals are too small and if you or mech only tighten nuts on connector, cable might still be loose...generally, I think that'd show up pretty soon and as intermittant odd gremlin sorts of things.

Parasitic drains from Aftermarket stuff that you don't think have anything to do with other elec. issues...really do. I've read often of diying this or that...or mech that gets things to work, but is pulling power incorrectly...often so it's drawing power continuously behind the scenes.

Shorts somewhere...loose fuses...get to know your ground locations...might be loose somewhere.

Ah, my favorite...

totally 'unrelated' failure/repair of another system--cooling, lubrication, CCV, PS, elbow...causing fluids to get into connectors and foul up signals to car.

OP, sorry for this, but is your car driving? Just lights and no other symptoms in engine or switches, etc?

Have you scanned for codes for free at Autozone? I haven't ever, but heard that's a service they do...bring codes back.

But first, look into basic things and report on other repairs.

I like a puzzle and would be glad to play! (Away all day though!)

HTH...sorry if you're already past all these suggestions!

Doug
 

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Discussion Starter · #11 ·
this may be signs of a slowly failing alternator...when you get undervoltage from the alternator, you will get most of the lights on the dash on because everything in the car isn't getting 12v like it should. Its really hard to diagnose something through the forum...but if you can get the lights to come on with the car running, see if you can get the voltage then and see what it is. When you say it wouldn't start, was it weak? like cranking slowly?
well it starts up fine now because i just got the battery fully charged at autozone, but then in a couple of months, the battery will die again from being drained (not to mention it was a brand new oem battery bought from and installed by tischer bmw in feb 2009 and ive only driven the car for 2000 miles since then)

First of all, did you have the battery load tested or did you just check the voltage? When a battery starts failing it may show a good voltage at low loads, you need to take it to the shop so they can perform a proper load test.

Regardless I'd highly recommend taking it to the shop and having the entire charging system checked. It's a system. Replacing one failing electrical component is rarely good enough, as one failed component will usually toast other components. If the regulator is bad it can toast the alternator and battery, so if you just replace the battery it will fail again. :facepalm: If you then replace the battery (again) and the alternator, they will both fail AGAIN. :facepalm: :facepalm: It's very costly to fix the charging system piecemeal. You need to have the entire system tested and then replace ALL the failing components.

Now I'm speaking about cars in general based on 10 years working for an parts/service center. Maybe someone else here can speak more specifically about BMWs and the E46. I still haven't got a code reader so I'm not familiar with the extent of the BMW diagnostics, which look really extensive. Anyone? :help:

good luck, I hate electrical problems.
well at autozone, they said it was a good battery, and considering they are a parts store with good equipment, im assuming the equip they had tested the load as well

Jone or Perry or both,

Mileage? Year? Sorry if I missed that.

Aftermarket things?

What other elect. work might have been done incidental to original problems?

I like the cleaning and replacing brushs, regulator, but haven't done this myself. Had alt out...should've stepped up my diying! Anyone with link or 'crib' notes on this...Mr. Juan? Alt in, think you said for both brushes and reg, right?

Anyway, OP...Don't forget the basics too that many skim over too quickly in diagnosing elect. issues...

Battery cables tight? With replacement bats. sometimes terminals are too small and if you or mech only tighten nuts on connector, cable might still be loose...generally, I think that'd show up pretty soon and as intermittant odd gremlin sorts of things.

Parasitic drains from Aftermarket stuff that you don't think have anything to do with other elec. issues...really do. I've read often of diying this or that...or mech that gets things to work, but is pulling power incorrectly...often so it's drawing power continuously behind the scenes.

Shorts somewhere...loose fuses...get to know your ground locations...might be loose somewhere.

Ah, my favorite...

totally 'unrelated' failure/repair of another system--cooling, lubrication, CCV, PS, elbow...causing fluids to get into connectors and foul up signals to car.

OP, sorry for this, but is your car driving? Just lights and no other symptoms in engine or switches, etc?

Have you scanned for codes for free at Autozone? I haven't ever, but heard that's a service they do...bring codes back.

But first, look into basic things and report on other repairs.

I like a puzzle and would be glad to play! (Away all day though!)

HTH...sorry if you're already past all these suggestions!

Doug
yeah the car is 02, with 62k miles, and no aftermarket stuff what so ever, all bone stock, no electrical work done that i know of besides changing the battery with a new one in feb 2009 by tischer bmw, and i checked and rechecked the battery area and connections over 10 times, they seem to be intact. i guess ill have to start with the rest of the electrical system of the car with ground and etc.

thanks everyone
 

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littlegti is correct. When you had your alternator tested, you only had it tested for voltage output. To get the full picture, you also have to know what the maximum amperage output is. You can have great voltage, but really sh*tty amp output, which could possibly ruin an otherwise good battery. Low amps would also have your car celebrating "Christmas" with all those lights. Get to a good indy to have a full charging system evaluation, or if you have the equipment, the voltage output of the alt s/b approx 13.2 to 13.8 volts. Amperage output can vary according to your cars equipment package, however it should sit at the 115 to 145 amp range with the idle at 2k rpm & all equipment off. HTH. Chas
 

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littlegti is correct. When you had your alternator tested, you only had it tested for voltage output. To get the full picture, you also have to know what the maximum amperage output is. You can have great voltage, but really sh*tty amp output, which could possibly ruin an otherwise good battery. Low amps would also have your car celebrating "Christmas" with all those lights. Get to a good indy to have a full charging system evaluation, or if you have the equipment, the voltage output of the alt s/b approx 13.2 to 13.8 volts. Amperage output can vary according to your cars equipment package, however it should sit at the 115 to 145 amp range with the idle at 2k rpm & all equipment off. HTH. Chas
So, sounds like alt issue that also hurt battery maybe?

You did try to pull the cables off, right? Just checking...I'm OCD!

Chas seems to know what he's talking about...as did Littlegti...I'd buy it!

New bats do go bad, btw, just randomly, so could be that too...but seems odds favor some reason for that.
 

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Does this car sit a lot without being driven for extended periods of time?

If so, get a battery maintainer/tender.

Check to see if you have an oil leak on the alternator, common issue that can cause problems.

Check any ground wires that may have been taken off at some point.

Also where are you checking the charging Voltage? Given the battery is in the trunk, there are a lot of connections that can be an issue.
 

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Discussion Starter · #15 ·
this may be signs of a slowly failing alternator...when you get undervoltage from the alternator, you will get most of the lights on the dash on because everything in the car isn't getting 12v like it should. Its really hard to diagnose something through the forum...but if you can get the lights to come on with the car running, see if you can get the voltage then and see what it is. When you say it wouldn't start, was it weak? like cranking slowly?
voltage with lights on and heater full blast = 13.8 to 13.86 and it didnt start weak, it started up fine once i had a fully charged battery
 

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Discussion Starter · #16 ·
So, sounds like alt issue that also hurt battery maybe?

You did try to pull the cables off, right? Just checking...I'm OCD!

Chas seems to know what he's talking about...as did Littlegti...I'd buy it!

New bats do go bad, btw, just randomly, so could be that too...but seems odds favor some reason for that.
yeah i pulled the cables off, and i took the battery out of the car to get it charged at autozone, i hope its not a case of new battery going bad

Does this car sit a lot without being driven for extended periods of time?

If so, get a battery maintainer/tender.

Check to see if you have an oil leak on the alternator, common issue that can cause problems.

Check any ground wires that may have been taken off at some point.

Also where are you checking the charging Voltage? Given the battery is in the trunk, there are a lot of connections that can be an issue.
i drove the car everday and it then it gave me this problem.... and i do have an oil leak from the oil filter housing :rolleyes: i checked the battery both at the trunk and at the front of the car where the positive terminal connection comes to the, trunk =13.8/13.86 volts lights on and heat on, engine = 13.6 to 14 volts with different combinations of accesories on (signals, heat, high beam flash, xenons on, rear defroster, etc..)
 

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Discussion Starter · #17 ·
ohh update, there is a connection at the back of the alternator that has nothing plugged into it, i found the wire that looks like its suppose to be in there but im not sure,its just been hanging all this time, anyone know about this?
 

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Jone,

The alternator has a large cable coming into it, bolted beneath the rubber boot back there, but it also has a connection...so a connection spot on the alt and a wire nearby undoubtedly want to join! If you can, spray plastic safe electrical cleaner in both spots and wait for it to dry.

I haven't done work on alt other than to remove it...but would guess that's a connection to the voltage regulator and is certainly needed for something...my guess is voltage regulation, but I don't know what that means specifically!

Also, nothing personal, but I don't think I'd go back to a garage that might've been doing some work on the car...they either forgot, or remembered to forget...or just randomly pulled on it...connectors on our cars seem to stay together quite well.... If it's a friend or yourself...bygones!

Doug
 

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Discussion Starter · #19 ·
yeah i really wanna put the wire on the connection but im just scared cuz i dont know what it is, if anyone knows, can you share some thought on it? i mean Doug if u say the connections are really stable, that means this connection thing must have been off for a year at least because the last time i took it to the dealer was more than a year ago, so im just currious as to what this connector is?
 

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my friend replaced the alternator, but forgot to tighten some sort of ground wire.
the alternator was reman and wasn't charging the battery, took it to a mechanic and he couldn't figure what the problem was, I took out the alternator and saw the wire was hanging freely...I attached it to the alternator and the alternator started working.
 
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