[jasonbimmer]

I think the voltage regulator is blown due to high rpm.
it came on first time I hit about 5000rpm then I let off it went off, then I hit it again and it didnt come on.
then I came to a stop it came on and stayed on.
used the instrument cluster to check voltage says 11.83 so clearly the battery is not being charged.
voltage does not vary with rpm so I think the regulator is shot.

 

[zhenkaaaM3]

Or the alternator is out. Might as well change it since your taking it out anyways

 

[jdstrickland]

Alternator or voltage regulator took a bye.

The alternator generates electricity by way of a pair of brushes. The brushes wear down. The brushes are part of the regulator package. Sometimes, the regulator can be removed from the alternator without removing the alternator from the vehicle -- I do not know if your BMW allows this or not.

 

[jasonbimmer]

Alternator or voltage regulator took a bye.

The alternator generates electricity by way of a pair of brushes. The brushes wear down. The brushes are part of the regulator package. Sometimes, the regulator can be removed from the alternator without removing the alternator from the vehicle -- I do not know if your BMW allows this or not.

it is doable but its easier just to remove the unit out and disassemble it.

 

[jasonbimmer]

went to NAPA and picked up a reman Napa alternator. worked for about 5 min and dead again.
I guess I need to get a brand new Bosch from ECS. Need new front grills too. ahhh, this thing is eating my wallet.

 

[zhenkaaaM3]

:rofl: its an alternator and front grills. how small is your wallet :rofl:

 

[jasonbimmer]

:rofl: its an alternator and front grills. how small is your wallet :rofl:

pretty small.

 

[smolck]

went to NAPA and picked up a reman Napa alternator. worked for about 5 min and dead again.
I guess I need to get a brand new Bosch from ECS. Need new front grills too. ahhh, this thing is eating my wallet.

Might want to trickle charge the battery before you assume the new alternator isn't working. If your old alternator wasn't charging the battery, it could have killed it.

 

[jasonbimmer]

Might want to trickle charge the battery before you assume the new alternator isn't working. If your old alternator wasn't charging the battery, it could have killed it.

no it starts fine and I havent been driving it cuz I got another car (thank god for owing a BMW!)
the new alternator just quit working after 5 min. when I go pull the battery, car dies so it IS the alternator.
when I say dead, I meant the battery light is on battery still has charge.

 

[jdstrickland]

no it starts fine and I havent been driving it cuz I got another car (thank god for owing a BMW!)
the new alternator just quit working after 5 min. when I go pull the battery, car dies so it IS the alternator.
when I say dead, I meant the battery light is on battery still has charge.

What!? You are not removing the battery from the car while it is running, are you? That practice was okay on your '65 Plymouth Duster, but is a huge problem for the electronics on a modern computer-controlled automobile.

How do you know that the new alternator is dead after 5 minutes?

 

[IrunBimmer]

Disconnect the battery and your problem will be solved

 

[Surrept]

Just buy a multimeter and check the voltage.

 

[jasonbimmer]

What!? You are not removing the battery from the car while it is running, are you? That practice was okay on your '65 Plymouth Duster, but is a huge problem for the electronics on a modern computer-controlled automobile.

How do you know that the new alternator is dead after 5 minutes?

because the battery light came on after 5 min. and I looked at the voltage it was around 11.8V means it was only running on battery. so I pulled the battery and the car died.

and no, dont worry about pulling battery, it wont cause any issue.

and yes I took the alternator back and they tested it, it was dead. probably not up to par voltage regulator, just died like the original one.

 

[jasonbimmer]

Just buy a multimeter and check the voltage.

E46 already has diagnostic hidden function so no multimeter is needed.

 

[klax]

I don't think one has the hidden diagnostic function if your car does not have the control stalk operated computer.

 

[jasonbimmer]

I don't think one has the hidden diagnostic function if your car does not have the control stalk operated computer.

yes you do. you use the left instrument cluster button.