Hi guys, I'm new here and I'm looking for your wise advise. Today I started my 996 99 c2 and the dashboard looked like a Christmas tree and the volt indicator was below 12. The lights that were on:
1) TC
2) The yellow triangle
3) ABS
4) Batery light

The car starts but I'm afraid not for so long, any idea guys? Thanks a lot.

 

Was the car sitting for a long time? it could be a weak battery. Worst case the alternator is about to go.

 

Mk, it was sitting for two weeks, and once I drove it I had de TC and ABS lights on for a while, I stopped the car and when I started it again they went off, but today all of the above ON plus the volt at 11,7 aprox, anyway the volt meter was never high, I mean 12,8 or 13 usually. But if it were the alternator, why does it have the TC, yellow triangle, ABS and battery all together on?

 

Because the alternator is not able to supply enough electricity to satisfy the car's electrical needs and the various systems that are sensitive to voltage are complaining.

Or it could be the battery is bad enough the alternator is max'd out supplying power to the battery with not enough left over for the rest of the car and the various systems that are sensitive to voltage are complaining.

I'm always a bit concerned about using a car that is manifesting this behavior as I do not want to risk ruining an alternator by trying to nurse a sick and dying battery any.

I prefer to identify the source of the problem -- for me it has been the battery -- and replace it and then ensure the alternator is OK. So far it has been.

 

OK, clear I had thought it had to do with the MAF sensor as the TC and ABS lights were on as well. I'll tell my mechanic to inspect the alternator and battery, thanks.

 

Seems like you have two issues going on. The fact that you're below 12v will throw up various lights. I would charge your battery and still see if it persists.

You indicated you had tc/abs on for awhile. This could be a bad wheel speed sensor.

 

Today I took the car to the mechanic, he meassured the battery volt (12,2) and the alternator volt (11,3) approx, so it was the alternator.
Yes, 2 days before the Christmas tree on my dashboard I had the tc/ABS lights on for a while. I read that it could be the MAF sensor, but don't know really, maybe it's as you say. My mechanic will take the alternator out to see what's going on.

 

When you said "awhile", I thought it was more than just a couple days. If the tc/ABS lights only came on a couple days before your alternator issue, I would most likely think they are related to the same issue.

If your mechanic has a good code reader(one that can read the abs computer/sub module), he'll be able to see any abs/tc faults.

 

You mean the alternator issue, and yeah I do hope he's got a good code reader.

 

Some mechanics mistake a bad alternator/starter cable for a bad alternator. Don't be surprised if a new alternator doesn't fix your issue.

 

...at last!! It was the voltage regulator, my mechanic couldn't find one for Porsche but he searched and found out Volkswagen uses the same alternator (amarok pickup) and he bought the volt regulator for that model, well it's running great again, thanks.