As the subject states, I need some help on a battery drain problem. The original battery was dead and even after I was able to charge it, it would not show and "green" in the window so it was replaced. I'm able to start the car every time if I drive it daily, but if I leave the car for a period of 2 days then the battery is drained to a point where I need a boost. After that, it's fine again until I leave it un-driven for another 2-day period. I've checked all courtesy lights, trunk and hood lights, etc. I don't know where the drain is coming from. How do I begin to troubleshoot this further?? GM says it could take up to 4 days to find the cause which would cost a fortune. I thought about just buying a battery disconnect switch just for the weekends when the car isn't driven. Other than my radio settings, would the system not having any powere affect anything else?? Any insight into this problem would be much appreciated.
Get a cheap multimeter that can measure current. Disconnect a battery cable and hook it in the line. If the current is more than a few milliamperes start pulling fuses.
A similar one I ran into a while ago was a little lamp in the rear view mirror. The guy didn't know he had one, bumped the switch and it is only noticeable at night.
In the meantime just disconnecting a battery cable (negative wire) will be adequate.
Sounds like a dead battery to me. (1) Internal battery drain might be caused by a shorted cell, or it might be just a slow short. (2) Any original battery that is older than four years is suspect. (3) You can do standard battery tests, but you have already confirmed the obvious.
Your choice could begin by either trade the car in on a new one or spend mega bucks and let the GM dealer troubleshoot and repair the problem. Don't be scared that the dealer estimated "GM says it could take up to 4 days to find the cause".
I recently had a electrical problem that required 1 hour troubleshooting time plus 1 hour repair at $ 75.00 per hour. Their diagnosis revealed that I had a underhood 40 Amp Mega Fuse blown. Yes, I had to bite the bullet and pay $150.00 labor bill plus parts. I did agree to let them repair my electrical problem.
If you choose the GM dealer, they have a everyday working knowledge and my experience is they will try not to lolligag and let the car sit.
Being a former U. S. Air Force Radar Technician and I am impressed at the caliber of the mechanics today and their professionalism.
You can troubleshoot this problem with a shop manual & wiring diagram & dc multimeter & some limited rudimentary tools yourself in your driveway with good weather.
To start with, I will save you grief and frustration of exercising your gray matter by sharing with you some secrets of automotive electricity.
Are you ready to "How do I begin to troubleshoot this further?? ." Hopefully you should continue to use the car like when it was new without "I thought about just buying a battery disconnect switch just for the weekends when the car isn't driven." At the very least, a battery charger should be kept available until you find the problem.
A wiring diagram would be helpful for your benefit to follow the current flow originating at the battery.
Remember, the one primary rule of troubleshooting is start at where the problem occurs such as Discharged Battery.
So, start at the battery: Determine whether it is a good battery when fully charged.
If time is a problem, Sometimes I have used a a good fully charged loaner battery.
If you have, can borrow, or purchase a DC multimeter with at least 10 Mega Ohm per volt input sensitivity: a. Insure all doors are shut, trunk lid closed, ignition switch and ALL accessories are OFF with key removed before proceeding. b. Disconnect the Negative battery terminal. c. Select, depending upon the meter, 10 Amp unfused scale. d. Connect the meter in Series between the Negative Terminal Post and Negative Cable. e. Don't be alarmed if you see a reading. If nothing is wrong the reading should range between 7 to less than 50 milliamps. f. If the reading is higher than 1/20th of a Ampere or 50 Milliamperes, this will confirm you have a excessive parasitic current draw. g. Record your initial reading as a matter of latter reference. Observe the reading with a door opened versus closed. h. Now here is your chance to become a auto electric expert by start pulling fuses and observing any change in the meter reading. Remember throughout this process if a door is open, your need to subtract your dome light draw from your meter reading. i. While you are performing these tasks please understand Parasitic and/or Static Current draws need to be understood. Key off parasitic current draws includes anything that requires a bias such as onboard computer(s) and a malfunction. Also consider these: entry courtesy lights operated by doors being opened and closed via door post switches, mercury switched gravity sensitive hood and trunk lid courtesy lights at light socket, If you are able to isolate the problem concerning the above, you may have to either remove bulb(s) or disconnect wire(s) until later.
Feel free "TR" to email me if you encounter any road block. I will understand if you decide otherwise.
"TR" wrote in message news:ce5m69$qt5$ snipped-for-privacy@news.eusc.inter.net...
I had *exactly* the same thing with my car. I took the battery back to Wally-World, as they had sold me the battery a few months earlier. They did a quick diagnostic on the battery that took 15 seconds and got me a brand new battery.
Vuarra
Quid quid latine dictum sit altum videtur. (That which is said in Latin sounds profound.)
Thanks for your replies. Here's another little test I did. My neighbour also has an Impala so we compared current draw with a meter. Both his and mine are drawing 1.2 A with the car off. To me that's high, but he has no problems with his car which throws me off. Also, this car has battery run down protection. Does that merely turn off any lights accidentally left on or is it suppose to electrically "disconnect" the battery via relays or whatever if the level gets too low. Overnight the voltage remains pretty high at 11.8v but after 2 days it's about 6V.
Are you sure about that 1.2 A? That sounds way high to me. With most multimeters meters you would have to use a 10 ampere scale
And, I think the run down protection is just an automatic way to turn off lights. Most cars have that now.
If you are indeed drawing 1.2 Amps you could drain a battery in two days but your neighbor would too. I will go with the bad battery and suspect that you had the wrong scale when reading current.
That is unless when reading your neighbors car you had the hood open and there was an underhood lamp that was on.
On second thought I think you did not leave the meter hooked up long enough to get a good current reading. It takes several seconds - perhaps a minute before the initial current settles down. I think that you will read over 1 ampere when first hooked up. Then after about 30 seconds to a minute it should settle down to something less than 0.1 ampere.
It looks like you just answered your question. 11.8 volts after running the car is too low. It should be in the high 13 or low 14 volt range. Check the voltage with the car running and it should be around 14.5 volts. Turn the headlights on and it should stay around there. You have either a bad battery or bad charging system. Take it to a shop and get it load tested. They can tell you in a few minutes if they are bad....
I bought an Olds that had a similar problem of running the batt. down over night. The previous owner had 2 shops look at the car and they couldn't find the problem. He put on a batt. disconnect to stop the run down over night. The car ran fine which is why I bought it.
I got a factory shop manual off ebay to help with the trouble shooting. While studying the problem I heard soft clicking from the engine after I had started it and shut it off. The idle air controler was cycling on and off. It wouldn't do it after the batt. had been disconnected and reconnected, only after the engine was run and shut off with the batt. connected. From the shop manual I found out the ECM controls the idle air controler. I got an ECM from the junk yard for $30.00 and it has been fine since. It was a bad ECM that made a ground for the idle air controler when the key was off.
That was eliminated after the meter was hooked up.
The static draw will be the static draw, unless he found a hood lamp, removed the bulb, then the draw would have went down slowly. As the battery located it's point surface charge.
rather than a diagnostic or electrical/drivability tech. There are classifications of techs in dealers, look at who's always doing R&R's&R's, brakes, front end and under car. Then on the other hand, look at the techs that are always doing the electrical spectrum of the vehicle, such as: diagnostics, fuel control, electrical ignition, electrical in car, electrical lighting.
There is no shame in being either, just some are more proficient or more comfortable with one, more than the other.
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