AAA came out and gave it a jumped it and it started right away. Now 2 things are happening.

1) Air Bag Light Is On

2) On my 20min drive to charge the battery Im not getting an alternator whine...sound you get when something is not ground correctly. Like where the pitch changes as the engine revs change? I hear it through the speakers even when the stereo is off. Could this be because the battery is still not fully charged?

Please help on both.

He AAA person did have to put the jumper in the fuse box to pop the hood to get to the battery.

I know worst case the dealer can reset the airbag light but it's the grounding thing that has me worried.

Thanks!

 

Alternator whine may be a sign of a mechanical imbalance, which often happens when one of the bridge rectifiers is blown. I am always concerned about jump starts, which can produce current surges and kill rectifier bridges and other electronics.

 

I have heard from multiple techs and read in manuals that you are never supposed to jump a car with a battery that has been excessively drained. Instead, you should trickle charge it first. Supposedly, the alternator can be damaged if you ignore this advice.

Not sure if this is your issue, but just figured I'd throw it out there.

 

Thanks for the great thoughts. I drove the car to work today and the whine went away. I think the battery just needed to get fully charged again.

Airbag light still on...

Jason

 

Can you please elaborate on what this is? I've not heard of bridge rectifiers before, but recently I've started to hear the engine 'whine' through the speakers when in 'AUX' setting (even without anything plugged into the cable).

Do they relate to the alternator?

 

I have no idea if your problem is that. However, when jumping a battery there is a risk of one of the alternator diode rectifiers to blow. When that happens the alternator voltage output varies in amplitude and causes a circularly rotating force on the alternator shaft destroying its bearings.

 

The application to the topic at hand aside, color me impressed - this is flipping poetic!!! The proof would make a great question for a physics or EE exam! (You'd have to know what a diode is and how it works, how an alternator works, characteristics of electricity, vector forces in relation to circular rotation, bearing function and tolerances, etc.)