Could a blown PS pump cause the alternator not to charge at low rpms

[bjl4776]

So my PS pump blew this week. Im at school and haven't had a chance to replace it. Im going to this weekend when i go home. But now my car doesnt like to even turn over if it idles for to long. My lights go dim, my cd player stop workin, and then my CEL, ABS and SRS light come on, and then the starter doesnt even click. Can this all be cause my low battery voltage. When im crusing at 3k rpm or so everything goes back to normal. Im just wonderin the PS pump is the root of my problems or if i should look elsewhere while im workin on the car.

[BillionPa]

replace the battery.

go for an optima red top, the one i got isnt supposed to fit in my car, but i made if fit anyway, and its much better.

[632 Regal]

sounds like the alternator isnt charging, does the belt look good?

[Morgenster]

sounds like the alternator isnt charging, does the belt look good?

Could the PS pump be drawing too much from the engine in idle therefore causing not enough power to the alternator?
I wonder cause sometimes when my idle is crappy the lights dim too.

[Javier]

take a look at this thread (http://www.bimmer.info/forum/showthread.php?t=17651).

Javier

Edit: Not sure about 520, but if the belt for PS pump and alternator is the same, yes the belt may be slipping due to a defective pump, causing the alternator to run very slow. Revving up, should relieve the situation.

[shogun]

replace the battery.

go for an optima red top, the one i got isnt supposed to fit in my car, but i made if fit anyway, and its much better.

If the engine is running, the power comes from the alternator and not the battery. So why should he change the battery?
Testing of battery and alternator is anyway easily done.

[TheEndIsNear]

Javier, is that information available for the 5-Series?

[Morgenster]

If the engine is running, the power comes from the alternator and not the battery. So why should he change the battery?
Testing of battery and alternator is anyway easily done.

So when lights dim when your idle drops to like 300 rpm it's normal?

[shogun]

@Josh: it is the same for the E34 and E32, because both use the OBC IV, if they have one, otherwise they have a clock installed.

@Morgenster: 300 RPM is much too low, even my V12 engines run higher at about 550-600 RPM.
At 300 RPM the alternator might not produce enough to supply the complete central chassis electronics with enough power and then the battery is drained too.
The bst is to use a good DMM and test
battery with no key in ignition
battery with ignition set to position 2
lowest point durung engine cranking
at idle
at around 1.500 RPM

Just today I use my unlocked PC while diring to check the voltage during driving: it was never below 13 V, usually around 13.4.-13.6 V.

[BillionPa]

i am saying replace the batt, because it sounds like the battery isnt charging properly at low currents, and not holding its charge.

check the alternator voltage when the car is running, it should be over 13.8

if its lower, then something is wrong with the alternator, possibly the voltage regulator.

if its at least there or higher, the battery is fried.

[BillionPa]

forgot to say, at 1500RPMS with the battery disconnected (ground wire while car is running, be careful that part isnt safe)

[Javier]

You can ruin the electronics, including DME.

Javier