ABS problems in 97 SC2

My abs warning light keeps going on. It happens alot in bad weather
like in last night's snowstorm in NYC. But it will also come in dry
weather. This will usually happen after the abs system kicks in. Also
when the abs system engages the red Batt warning light will flash for
a second. Sometime both the red brake warning light and abs light will
come on. In either case I still have brakes but I'm sure I don't have
abs.
When this happens I will turn off the car if possible and let the
system reset.
This works but last night those lights came on again. What is
interesting is that the "traction active" lights came on while I was
driving over ice telling me the traction system was working.
I thought that if I didn't have abs the traction wouldn't work either
because the two systems are tied together. I'm sure the abs wasn't
working though because when I tried to stop on ice the car started
swerving and I did not hear the abs kick in.
I have had this problem looked at twice by my local mechanic. Each
time he runs the system through his diagnostic computer and each time
the computer shows that the system is ok. He even tested the car with
the computer while driving it. The last time he checked the system was
two days ago along with the cars scheduled maintenance. The car has
about 65,000 on it.

If anyone has any idea that could shed some light on the problem and
help my mechanic find the problem I would greatly appreciate it.
Perhaps I should just bite the bullet and take it to Saturn.
Thanks for any help you can give.

Harold

 

Given that the battery warning light sometimes comes on, I would suspect low
charging system voltage. It seems to be a somewhat common problem on the
S-cars that the alternator can be bad, and although still charging, not
putting out enough power. The ABS system will complain if the electrical
system voltage is too low for it to function properly.

 

Would this explain why when my mechanic tests the alternator he says
it's charging ok?
The thing is when the alternator is being tested, even with a full
load of a/c etc, the car is motionless. It is only when the wheels are
turning and the car is in motion that the abs goes out. Also when the
a/c is running the dash lights are abnormally dim.

 

Depends how they tested it. If they consider it to be OK if it's charging at
all, that doesn't mean much..

 

I had him put a new alternator in thanks to your reply. Everything is
running the way it should be now. Unfortunatly the warrenty was out on
the old alternator (this is the second time I've had to replace the
SC2 's alternator. Last time was 10/02). He also replaced the device
that keeps the tension on the alternator belt. One more question. Can
I expect to replace this alternator in a year? Is there anything I can
do to keep it healthy?
Thanks for your help.

Harold

 

Yup. Replace the battery.

Bad alternators kill batteries, and bad batteries kill alternators.

If your alternator was going, it probably damaged your battery.

Since batteries are relatively cheap (compared to alternators and the labor
in replacing them), I would suggest getting a new battery.

 

3 alts and 3 batts on my 97SL2 - my dealer is or was warranting alts for 3
years so my 3rd was a freebie...
....I like what Kirk says about the two (batt and alt) needing to both be in
good working condition.

 

Now that I've had the alternator replaced all the system on the car
seem to be running fine. But my engine is noisy. When I popped the
hood it sounds like it's coming from the alternator. I will be
bringing it back to my mechanic but I want to know to if this is
because of the extreme cold we've been having here in NYC. It hasn't
gone above freezing since the alternator was put in last week and in
most cases it's been in the low teens. The alternator remains noisy no
matter how warnm the engine gets. It sounds like something needs
lubication or perhaps a loose belt. But the noise definitly sounds
like it's coming from the alt. Is this normal?

 

It's not normal to get that kind of noise from the alternator, regardless of
the temperature..

 

It turns out it was the water pump making the noise. I had it replaced
and everything's fine.