Battery Drainage

You can pull fuses one at a time to narrow it down to a specific circuit.

Won't that take a LOT of time.

Re-reading that, I see it wasn't too clear. What I meant was, while you have your ammeter between the battery and the cable, pull the fuses one at a time (or several at once). If the current draw goes to zero, or nearly zero, you know the culprit is on that (or one of those) circuit(s). I was just trying to expand a little on your suggestion to 'disconnect' items one at a time. Sometimes it is easier to pull the fuse than disconnect it. Another thought for OP, some items such as dome lights are switched after the fuse. In those cases, a short between the light and the switch will not blow the fuse, but will make the light come on. Make sure you check the trunk and under-hood lights as well.

Well, I re-read my response and discovered that I said "volt" meter. Of course, not being a sparky, I failed to say set to amps, cause I already knew that. Watching the voltage drop wound really take a long time, too.

Anyway, it occurs to me that blocko is a baker, so now I'm curious as to what tests were performed. Not that bakers don't know about cars.

It could be a short someplace....You need to trace it out...get something to test current flow, isolate components one at a time until the culprit is exposed..could just be a bulb shorted out...

http://www.ifitjams.com/circuit.htm

http://www.ehow.com/video_5113316_troubleshooting-auto-electrical-short.html

http://www.amazon.com/Power-Probe-Ultimate-Automotive-Electrical/dp/B000KPU8MK

I'm not so sure. If it is shorted out, why didn't the fuse go? And if the fuse didn't go then how has the wiring survived the discharge current from the battery into the short? Beats me!

It might not beat an experienced vehicle electrical technician. It might be worth taking it to one.

The contact point that's shorted is probably small and acting as a resistor and limiting current flow would be my guess...sort of like leaving your lights on...This happens with motors all the time...

Hmmm. Yes, I suppose that's on the possible side of plausible.

Turn the headlights off.

As stated, there is a short circuit somewhere. lyn and SolarEagle gave directions on how to find the culprit circuit. Finding the short within the culprit circuit is usually time consuming, but this is the only thing to do. It will not repair itself.

Or, automotive electrical repair shop. Good luck, and happy hunting.

It could be a relay,

your batt. under any load.. even mini current flow is not good. You may have a bad cell in this batt. How old is it. If you have a vehicle built as new as 20 yrs. ago, you have computer that always pulls mini current even when the car is "off". Also notice if the alternator is charging. good luck.

Have you checked your trunk, hood and glove box lights (if equipped) to ensure they are off when closed?

blocko,

How old is your battery??

Once you have eliminated any possible shorts in the system or faulty equipment, it is time to start looking at the battery itself.

Old batteries, usually will show themselves by their inability to hold a charge, a failed or failing cell will also show up initially as an inability to hold a charge.

Next look at the alternator to ensure the battery is being charged properly.

Next step see an auto electrician, before the minor fault the you can't find and we can't identify over the net becomes a major fault that becomes expensive to fix.

Regards,

Sapper

GA.. I agree! Start AT the problem and work outwards throu the rest of the car!

GA

I re-read the original post. If blocko has pulled all the fuses and there's still a drain, it's most likely one or more of the diodes in the alternator.

If you have Advance Auto test the batter, you should be aware that they have two battery tests. One takes about 10 minutes, the other takes about an hour. I had a battery in my Suburban go bad, but the short test showed it to be good. After spending a week checking everything else, I went back and had the long test done. It showed a fault that the short test missed. Replacing the battery then solved everything.

Check the insulation on the main +ve cables to the starter and fuse box(es).

This was a common occurrence in the old Leyland Mini, which had the battery in the boot. The cable insulation would wear at bulkhead if the grommet was not properly seated.

thanks this is the most reliable response iv received so far and will work on it asap

I like it!! GA from me

Lots of good advice in this thread. I'd suggest this order:

1) get battery and alternator tested for free. I use Wal-Mart.

2) If they are good, then put a cheap ammeter ($5 at Harbor Freight, etc) between the battery + term and it's disconnected cable. Start with the highest setting and work your way down as needed. You'll see some current flowing. Pull fuses until it drops a bunch and that is your bad circuit.

Now in today's cars there will always be a small current, maybe 10-20 ma, due to the clock, alarm and other devices that need juice all the time.

You forgot to mention to "not try and start the engine".

As starting would probably vaporize the ammeter......making a mess!!

I run into similiar problem in the pass. I learned that the Shock cause some of the cell crack and shorted. It drain quick. You might need to replace battery and checking for the vibration absorter which is mount under battery support plate.

Hello. It is important to let you know that some of the suggested methods to determine battery drain are no longer valid for modern,computer controlled and installed electronic devices automobiles. You failed to mention make and model or what accessories are installed.So if you are working on an old vehicle,(pre electronics) and your test lamp lights when it is installed between the battery and cable, you probably are seeing a drain on the battery that should not be there.On a modern vehicle however , complete with ECM,PCM.Electronic voltage regulator,digital clock,memory seats, twighlight sentinel etc.when you place your test lamp or voltmeter between the battery and cable, it is proper for the voltmeter to show voltage (often 12 volts) and for the test lamp to light.The only correct way to diagnose an excessive battery drain on a modern vehicle is an ammeter with ranges from milliamps to 20 Amps.The most accepted normal parasitic draw is between 25 and 35 milliamps.This test is done after a wait period of 3 minutes to permit the electronics capacitors to charge which often can pull 6 amps for a minute.Hope this helps.

You need to look at your alternator it may be taking the battery down with the engine not running and only above certain voltages thus not when you are testing.

I recently had something very similar happen to me. At first the battery would go dead if the car wasn't run for about four days. Then it started to happen after 2 days. I went out of town, and disconnected the battery for over two weeks. It started up fine. About a week later it would go dead after a few hours. During this I put my Fluke multimeter in line with the battery, and measured current while the car was off. I even put the meter in recording mode. I never saw a spike in current. Eventually I replaced the battery, and all has been fine since. Perhaps there is some intermittent inside the battery. Try swapping it with a known good battery and see if the problem goes away.

Starter coil.

disconnect cable from starter and monitor for symptoms again.

This happens on my 2002 Jeep and has caused a new battery to go flat very quickly. Make sure that when you remove your key from the column that the lock is not in between detents. This can happen on older, more worn locks, and when it does there is quite a bit of current still flowing. Easiest way to detect this is to try removing the key as you rotate it; carefully though because if you force it may jam the column.

Another thing to look for is a poor connection between the battery, connector, and the cable. Any corrosion or looseness there will set up a high resistance (relatively speaking) connection that may allow enough current out of the battery to run the car (low current = low voltage drop) but not enough for starting and/or recharging of the battery under heavy loading conditions. Unloaded everything looks good but fails under heavy load. Use a sharp probe and stick it in the positive battery post with the other probe through the insulation on the battery cable. Wiggle the cable and see if the meter deflects or the test light flickers, a sure sign of a poor connection between the probe points. Similarly for the negative cable to a clean spot on the engine.

One last thought, many years ago I was working under my Olds under poor lighting conditions when I spotted a glowing point out of the corner of my eye. Turns out that a cable had chafed through and was contacting the chassis through just enough wet road grime to conduct and cause a small arc to appear. When I wiggled the cable it went out. DC is funny stuff especially if there is any inductance in the circuit.

Don't wear any metal jewelry and make sure your tools are well insulated, the shaft of a screw driver across the terminals or to ground can result in an arc that won't go out, a visit from the Fire Dept. and a trip to the ER for severe burns.

If you have disconnected all the fuses etc, then many answers supplied here do not apply -- accept those having to do with "unfused" things, like the alternator (which may have a fusible link or circuit breaker at the battery terminal). (Starter issues are incredibly unlikely -- because for a short in the starter to do anything, the solenoid would have to be pulled in, meaning the car would be sitting there cranking all the time.)

Borrow a DC clamp-on ammeter. Otherwise, you run the risk of damaging the ammeter (or at least blowing the little fuse) in a multitester, most of which are rated for 10 amps. Put the clamp around the ground cable. Measure the draw. Disconnect the ground lead, then disconnect the alternator output lead (typically the fat one at the alternator). Reconnect the ground cable. Check amps. Be sure the disconnected alternator lead does not touch any thing metal.

(Be certain you are not working with wrenches around electrical part with the ground cable still connected. Things can go Boom. )

But in any case, measure the draw with everything but the alternator disconnected. If the battery goes dead in a couple hours, the draw must be quite high: ~20 amps if the battery is good. A failed alternator diode could cause that sort of draw.

Report back with draw with alternator in and out of the circuit.

There are many good suggestions here to diagnose the problem - one possible cause could be a relay in which the normally open contacts have welded together.

It would supply power to its normal load but not blow any fuses - It could supply the fuel pump perhaps or some other heavy load and show no other symptoms.

Two questions:

1. WHERE ARE YOU!!

2. what are the make, model and year of the car?

If you are located in the South of France (for example), much of the advice would be of no value. I doubt they have Harbor Freight there. If the car is only found in Europe (for example), I would leave that to our European fellows to troubleshoot.

A small bit of information can go a long ways.

Bill

I bet he/she is a US citizen, as they forget SO easily that there are nations and lands existing on this planet!!!

....and they say the Brits are insular!!!

Two other areas to consider are the make-up lights in the visor and something like an iPod or GPS with a faulty battery plugged into a cigarette lighter (are they still called that?)

Has a friend whose wife left the visor light on, and my Garmin doesn't hold a charge all that well so if I leave it connected and don't use the car for a week or so I sometimes have problems. BTW, that's on a relatively new battery.