My 1999 Magnetic Red Convertible seems to randomly run down the battery after just 2 or 3 days. Other times it will last for 3 or more weeks without a problem. A couple of times when I hook it up to jumper cables it immediately starts a chattering noise in the area of the right front headlight. I've seen on the web that the headlight control module is located in that area and how it can sometimes deplete the battery when it is bad. Or could it be a sticking relay of some sort. Any ideas?

 

Here's a couple links for you.

http://vettetube.com/view_video.php?...25f49408d959ca

http://vettetube.com/view_video.php?...3c1a84ce5276e9

 

My 99 Dies after a few days also. Mostly does so when I set the alarm and leave the alarm set for several days.

I get better results by not setting the alarm while it is parked in the garage.

But I have come to the conclusion that my baby NEEDS to be driven everyday to avoid this. So I just hop in it after coming home from work and use it to go get my little boy from school. Then we take a short drive down to the coast to relax and come home. What better way to avoid battery issues

No battery issues when I do this.

 

I've had simular problems with my one year old battery. I did two things that made a differance. 1. Remove both battery cables and clean both cable and battery surfaces. (As electricity passes from the cable to the battery terminal it can leave a microscopic deposit between the connection. This film builds and acts like a resister that can reduce the charging of the battery, particularly if the connection is not clean and tight). 2. I found that the cable connection at the starter motor was not snug. I loosened the nut, wiggled the cable around the terminal sprayed with WD40 and retightened the nut. In my case, Problem solved.
Sarasota Chuck

 

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 car eats batteries. Theres a 20MA drain even dormant. If you dont 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’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/show...rent+draw+test

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 mins (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.

 

DeeGee's advice is perfect....follow it!

 

Thanks to all. I will check the draw and probably just put a tender on the battery. As for daily driver.. I'm in Iowa, we're lucky to any acceptable driving weather each year, especially in March and April.

 

I’ve had this issue since January of this year. I replaced the battery 7/28/10 with one from Oreilly auto parts. If I drive the care everyday it’s fine but if I let it set for 3-5 days the battery is dead. I just returned home from a 10 day business trip and the battery was completely drained. So I charged it back up and performed the test in Bill Curlee’s post. During the test my amps would sit at 12 -13 and then to 5-6 amps and finally to .05. This was done prior to training the key fobs, after training the 2 fobs it dropped to .06.

Is .05-.06 milliamperes an acceptable range or should it drop to .02?

 

Stolen

Well this will certainly come in handy With the amount of times it comes up here, I'm thinking this post will be linked a lot.

Thanks DeeGee