went out to the garage today to find the battery dead. the battery is new. but opened the hood and heard a buzzing sound from them passenger side headlight motor. pulled the fuse and it stopped. what is going on here. where should I start looking. everything worked as it should the day before

 

The headlight module, a black box that is supposed to turn off the headlight motors when the current spikes when they hit the stops (either up or down), is located under the passenger headlight. Check if noise is coming from there. They are expensive to replace.

Was it a buzzing sound or a machine gun sound (bad gear, but should shut off after 10 seconds). Any problems putting lights up or down, any noise?

 

It was a more of a buzzing and clicking not like a bad gear I had that problem on my 94. What gets me there was no interior lights no nothing but yet the noise until I pulled the fuse

 

Do your lights work okay (with the fuse back in)?

Guess you need to charge the battery. How long has the car sat without starting it?

Did you pull Fuse #3 for the right headlight motor?

 

Yes pulled #3, and 4. Lights worked fine last night

 

You never answer ALL of my questions.

How long has the car sat without starting it?

You do know that C5's will drain a battery if they set un-used for a period of time. Reserve Capacity should be 120, this is high, I bet your new battery does not have this rating. If you are going to let it sit, use a battery maintainer on it.

When the battery voltage gets low, all kinds of things malfunction. Try pulling up your codes.

Here is a post that Dee Gee posted on what causes battery drain:

Identifying Battery Problems
The C5 eats batteries unless you take some regular precautions. If your battery continually dies its either the battery which is on its last legs or something on the car.

You also need to look at how you use the car. Is it a daily driver? If so the battery should be getting a good top up every day so you may have a problem.


Is it a DD but you do short trips? If so you'll be taking a lot out of the battery every time you start. For a short trip, say less than about 20 mins, you won’t top it off properly. Eventually it'll drain.

Is it a weekend car. If so, this takes a lot out of your battery. There’s a 20MA drain even dormant. If you don’t drive the car for a reasonable time every week or so, it'll kill the battery. In this case you really do need a battery tender.

You’ll know when your battery is bad. As it gets low you may get strange electrical indications (random warnings and U fault codes). As it gets lower it may drop the memory settings or defaults such as HUD settings. Eventually you’ll get the dreaded chattering relays in the footwell and eventually the lights on the IPC will disappear.

Most batteries can be recharged quite successfully, although AGMs are harder. Start by checking the charge on the battery. Don’t read the DIC when the car is off. The value you see on the DIC is alternator output when the car is running. It will always measure an inaccurately low voltage on the battery when the ignition is off and figures of 11.0V to 11.9V is normal in this case. With the engine on, the voltmeter should show between 13V and 14.5V. You need to measure voltage across the battery terminals using a digital multi meter if possible. A fully charged battery measures 12.7V and a fully discharged battery measures 11.9V. Partially discharged batteries will give a reading somewhere in between.

If the battery is low give it an overnight charge (or put it on a battery tender until you get a fully charged indication) and retest it. A true test is under load and Autozone will do that test for free.
If you have an AGM battery like the Red Top and it has been deeply discharged it's harder to recover it. This might help:
http://www.youtube.com/watch?v=dIoaL3DWWEg

If you’ve recharged it and it still runs down, then you need to start looking for excessive drains. Bill Curlee posted a good method for checking:

http://forums.corvetteforum.com/1567522286-post590.html

There are some common faults which are well known for causing problems:

First to check is the interior lighting rotary switch on the drivers panel. It’s possible for that to be turned on as there’s a setting (fully clockwise) which bypasses the auto off function. Turn it fully counter clockwise and check after about 30 minutes (preferably in the dark) that the interior lights have gone off.

If it’s not the lights something has failed or is badly installed.

Have you fitted an after-market device which draws current? Typically it’s a cellphone charger, radar warner or a similar device that’s the problem.

If still no joy, you need to start pulling fuses to identify the problem.

The power seat switches on the side of both seats are notoriously unreliable. The switch becomes sticky with use and can stick in the “on” position. You shouldn’t damage the motors as they are thermally protected. The fuse may blow so worth checking (Fuse 36 20A in footwell).

The driver’s lumbar motor can also cause issues so check this too (mini fuse 3 15A in footwell). The seat controls connect under the seat. Pull the connector and if the drain stops that’s your problem.

Less common but not unheard of are failures of the headlight motor control module the alternator and the Bose Amplifier under the dash on the driver’s side.
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2002 A4 Convertible, Mag Red II
Euro head and tail lights, Z06 screens, frame savers and rocker rails, Pioneer AVIC X1R nav/DVD player, EE catch can.

 

the car sat over night without starting it.

 

Wow, seems like you found your problem, I bet it is the headlight motor control module.

The above post should give you all other possibilities and how to trouble shoot for them.

Good luck !

 

Hmmmm....you sure about that? The headlight control module chattering/buzzing is a classic low battery condition. Something else may be draining the battery, and the control module is just responding to the low voltage. I would be doing a current drain audit, before I called anything bad.

 

Good point, I did not know that "The headlight control module chattering/buzzing is a classic low battery condition". He should follow the procedures outlined in my earlier post to find the source of the power draw.

 

I should also say that the 12 disk changer in the trunk was making all kinds of noise

 

Great info in post #6.......what have you checked out?