Problem with Charging system

saurabbhatia · #1 (**permalink**) 10-30-2003, 06:22 PM

I have a 97 M3.

It has Valeo Alternator. It seemed as the current Alternator was only charging at 12.33volts. Was getting all the interior lights dimming and ABS and ASC lights coming on and off.

So I order a new Alternator install it and NOW the Charging is only giving out 11.43volts.????

WTF.. Can it be the Alternator or can there be something else wrong with the Electrical System???

I have bought a new battery only one week old
I don't have any Underdrive pulley.

PLEASE HELP

tdc · #2 (**permalink**) 10-31-2003, 09:29 AM

Sounds like you have a parasitic draw somewhere. Do you have any aftermarket electronics on the car? If so, I'd grab my multimeter and check all the wiring and make sure everything is connected properly.

Also, I don't know why you changed your alternator when it was charging at 12.33V. That's what your battery is supposed to be charged at. Under load it will drop down to 11V.

saurabbhatia · #3 (**permalink**) 10-31-2003, 09:44 AM

well I was told and remember from old cars that it should be at 13.5 or better. and underload it shouldn't drop below 12.

As far as a system nothing on the car. While i'm driving the battery dies I don't have anything on just the car is runing and it seems as the alternator doesn't charge the battery..

M~BeBoT · #4 (**permalink**) 10-31-2003, 10:13 AM

Parasitic draw is when the car is off.
Where did you measure the output voltage at the battery or at the alternator?
If output is fine from the alternator and low on the battery then you have some resistace in the line so there is a voltage drop going to the battaery! So double check!
Also check if the belt is slipping!

saurabbhatia · #5 (**permalink**) 11-01-2003, 07:14 AM

Just spoke to my mechanic. It seems as the car Charges when it wants to. He has checked for a Draw. No Luck.. Can it be the Belt it to tights or something?