Hi,

Yesterday my wife was driving the A6 and she said the battery light come on once when she started the car but went away. After driving in the city for a few kilos the car just went completely dead; I took the battery to Canadian Tire and they checked the battery and said the battery was dead; I replaced the battery today started the car the light is still on; checked the voltage it is 11.6v.

So can I say it is a bad alternator? Or is there something else I should be checking?

It is a 99 A6.

Thank you.

 

You need to have the charging system checked. If you were in the states I'd sy to go to Autozone. They connect a machine to the battery and are able to test the complete charging system incluyding the battery and alternator.

 

You need an alternator.

 

Check the ground strap between the chassie and motor. Don't rely in it just being tight -- remove the strap and clean the sutfaces before reinstalling it.

 

Canadian Tire is even better than Autozone. Your battery should be putting out 2.2 volts per cell, or 13.2. The alternator should be putting out around 14+ volts to power the car and charge the battery. Get both a battery AND an alternator test. Sounds like the alternator has failed, but be sure. If you need an alternator, they can be purchased rebuilt for about US$200-250 online. I put in a rebuilt alternator at 75k miles and it has lasted for the last 90k.

 

Thanks guys.

I've already got the battery checked and replaced, the light is still on, measured the voltage it was at 11.6v.

If I need to get the alternator tested, do I need to take it out first?

thanks.

 

Simple instructions --- take the car to the guy with a tester and he will be able to tell if it is the battery or alternator.

 

You measured 11.6 volts where? At the battery posts? With the engine running? Did you charge the new battery before installation? Did you clean both posts and terminals?

AS pointed out above, a fully charged battery will measure 12.8 volts or more. 11.6 menas a dead battery cell IF you measured at the battery posts. The car can actually start and run on a battery with a dead cell, just not very well. Just because the battery is new doesn't mean it is any good!

On the other hand, if you measured the 11.6 v somewhere further away from the battery while the engine is running, then your charging system is not working and you need a new alternator. The alternator can be tested on the car, but you run the risk of the car dying on the way there. Changing the alternator means removing the front bumper.

Good luck,

Bob

 

Sound like your alternator