.13 mA draw on battery normal?

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sargentrs

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Excuse for asking dumb questions but I'm not so good at electrical. My battery is losing about .01v every 8 seconds. Needless to say, overnight, she's too dead to start. Just started yesterday. Checking a few things I find out I have a .13 mA (my VOM is set on mA and the digital readout says .13, would that be 13 mA?)draw on the black wire on the alternator, same on the starter circuit from the relay and all the way up to the positive battery post. Zero draw at the voltage regulator harness, unplugged. I'm assuming I have a bad alternator? Something else I need to check? Thanks to everybody for all the help ya'll given me getting this baby rolling!
 
If you are reading your meter correctly, .13 ma is OK.

Unhook the battery ground and put the meter in series. What do you read?

You are checking the alternator how? Unhook the wire and put the meter in series between the output stud and the black wire?

What model is your meter and what scale are you setting it on? AND what connections (meter connectors) are you using? Also, you have a way of making certain the meter is actually working? Many of these have an internal fuse on current, and they can do "wierd things" if the fuse is bad. Take a small lamp......like your 12V test lamp.......and measure it's current draw.

By the way, here's an interesting read from Fluke on troubleshooting

[ame]http://assets.fluke.com/appnotes/automotive/beatbook.pdf[/ame]
 
Meter is an INNOVA 3320. About a year old. Leads are in the 200mA Max fused ports. Car not running, key off. Held the leads on the battery posts, cables connected and watched drop consistently .01v every eight seconds. Run the engine and alternator is pushing 13.5+ volts back to the battery. Kill it and the voltage drop starts again. Remove positive cable and voltage drop stops. Unplug voltage regulator and slows down to about .01v drop every 5 minutes. Connect black lead to neg batt post, red lead to alternator stud, set VOM to DC may and read .13. Same at starter relay and starter. Removed batt ground and still reading .13 at alt stud. Zero at ground cable disconnected. Zero between output stud and disconnected black wire. 12v test light reads .13 alsoat battery.
 
Unplug voltage regulator and slows down to about .01v drop every 5 minutes. .

You need to be extremely explicit with your connections so I can follow. Are you saying, above, that you unplug the regulator WITH KEY TURNED OFF?

Connect black lead to neg batt post, red lead to alternator stud, set VOM to DC may and read .13..

Explain further EXACTLY how you did this

EG: If all wiring is hooked up "normal"

If your meter is set for mA

And you hook one lead to the alternator, the other to battery NEG, this should result in either damage to the meter or a blown current fuse in the meter


Same at starter relay and starter. .

No understanding of how you did this


. Zero between output stud and disconnected black wire. 12v test light reads .13 alsoat battery.

Confused



As I said earlier, test your meter. Take a small 12V bulb, or your test bulb, and measure the current. You can look up bulb draw (current) and wattage on the www

An 1157 stop / tail example, is around 8 watts for tail and 25-27 for stop. Watts is voltage X amperage, so say, (estimate) 24 watts divided by 12 volts is "in the neighborhood" of 2 amps

So for that you need higher than a 200 ma full scale

more.............
 
http://i.walmartimages.com/i/p/00/04/21/73/03/0004217303320_500X500.jpg


I see now. Here's the thing about measuring current. Current "meters" (ammeter, milliameter) is always in SERIES

And, you can "blow them up." (Or at least blow a fuse)

Whenever I attack a "draw" problem, here's my general strategy.

YOU WANT TO PROTECT YOUR METER. How? to do that?

Start out with a lamp. I start with a stop or tail lamp.

Disconnect the NEG battery terminal and put the stop lamp in series. Make sure EVERYTHING is off, the trunk lamp, dome, radio, unplug any cell chargers, etc.

Any light?

If not remove the stop lamp and replace it with your 12V test probe / lamp. This will be a SMALLER bulb. Any light? look carefully!! Use in subdued lighting if you can.

If you see nothing, Now put your AMMETER in place of the bulb. Use the "DC 10A" switch position, and notice that you will use the far left and middle probe connectors

See what this reads. Look up "what is the maximum" of your mA scale in the book (Did I read you said this was 200mA?

Anyhow important to find that out. IF your 10A switch position read LESS THAN the "mA" scale is capable of handling, unhook the meter, reset your leads for the center and far right connectors, and set the switch on "mA."

Take a reading.

UNHOOK the meter there in series with the NEG battery lead. ALWAYS "recheck" first with your small 12V test lamp BEFORE you hook the meter back up

Make CERTAIN you have removed any dome lamps or when you activate them you will DAMAGE THE METER (opening the doors)

Now start unhooking "stuff."

Pull fuses out one at a time. Check the reading.

Pull the VR plug off. Check the reading. THIS SHOULD HAVE no effect with the key OFF

What I'm getting at, here, is that if you put a load on the system (like the dome lamp) this will "act like" a short as far as the mA meter setting is concerned. The meter may or may not be protected or fused.

By checking first with your 12V test lamp, you can see if it glows dimly, probably safe, or brightly.......dangerous.

Unhook the alternator stud wire, see if that affects the reading.

==================================================

FOUND the destructions for the meter

https://www.iequus.com/Product/3320/Auto-Ranging-DMM

[ame]https://www.iequus.com/Content/Support/Manual/93-0041.pdf[/ame]
 
Excuse me for buttin in, but the way I read the description, you're reading battery voltage with the "amp" scale? Cuz you said you held the probes on the battery posts. 67Dart273 said, "put your meter in series" meaning break either hot or ground side and complete the circuit with your meter in amps. Make sure you fuse protect better than the meter. Some meters have a 10amp max position, I'd start there using a ATO5 or 7.5 to protect your meter.
 
^^ and according to the destructions for that meter, the 10A scale is NOT protected ^^
 
.13 ma would be 130 milliamps and not the assumed 13 milliamps. This is what 13 milliamps would look like on a multimeter or scope, .013. Now I may be wrong on this part and will gladly be corrected but on modern vehicles a 50 milliamp draw is a GENERAL rule of thumb as being acceptable and looks like this .050 on a meter or scope, but I have no experience with the older cars to say whether or not that spec. still holds true. Thank You
 
.13 ma would be 130 milliamps

No, not correct. But I'm not familiar with this meter the OP has

.13 AMPS would be 130 milliamps.


. This is what 13 milliamps would look like on a multimeter or scope, .013.

This is only correct (again) if you are reading an AMPS scale. A mA scale should read the quantity "directly." That is, if you are on the AMPS scale (10A) .130 would indeed be 130 mA

13 mA on a 200 mA scale should say 13 or 13.x, etc

But if you are on the 200 mA scale, it should show 130 ------- or possibly 130.X depending on the amount of display numerals in the display
 
This gets into differences of meters, switching, and connectors, but I would expect the OP meter to read the same as below, using the AMP vs the 200mA scale



Here are some examples on one of my old Flukes. In the top photo, we have the probes plugged into the "10A" connectors. The reading, ".17" means ".17 of one amp" or 170 milliamps or "mills."

http://i59.tinypic.com/jggmli.jpg

In the photo below we have changed to the 300 mA scale. This reading, 42.4, means 42.4 milliamps, or 42.4 mA. To convert this to amps you just move the decimal so .0424 amps

http://i58.tinypic.com/2h5u0ld.jpg


In the photo below, still using the 300 mA connectors, we are reading 132.2 ma, milliamps, or "mills." If we were to move the connectors back to the 10A position, and assuming the two scales are completely accurate, the reading would become .1322 A
http://i59.tinypic.com/315hcwj.jpg
 
I think the battery voltage dropping slowly after the engine is turned off is normal, probably due to capacitance and electro-chemical effects. I see that in my cars. Disconnect it and check it after an hour. If <12.6 V, the battery might be bad. Autozone will test it in the car for free.

I also suspect you blew the fuse in your multimeter for "A" mode. It is easy the do. The 0.13 mA might be a stray reading. That is very close to zero and few multimeters can resolve 130 uA.
 
Wow! You guys are so over my head. I've got a lot to learn apparently. Let's see if I can explain myself.

I replaced the carb, new carb was bogus, put the old carb back on, and took it for a test drive. Everything worked and she ran fine. Parked in front of the house, killed it, started it, killed it, started it, just to check that she'd be ok the next day. Got in to go to work the next morning and she was dead. Nothing happened when I turned the key, not a click, no dash lights, nothing. Figured with all my start, run, kill, etc trying to get the "new" carb to function, I drained the battery. Got home yesterday and she fired right up. Maybe sitting in the hot sun all day the battery recharged itself enough to start? Idk.

In the picture of the meter above. I had the black probe in the center hole and the red probe in the RH hole. First, I had the switch turned to the green circled "Battery load test" 12V position. Touched the black lead to the center of the - post and the red lead to the center of the + post. With the key turned off and both battery cables connected, the meter read 12.75 V. Turned the key and she cranked right up. Held the leads in the same position and the meter read 13.53 V. I assumed the alternator was doing it's job.

Killed the car and held the leads in the same position. Meter read 13.08 V but dropped rapidly down to 12.78 V and continue to drop slowly at a rate of .01 V about every 8 seconds. When it got down to 12.66 V I started the car back up and everything acted the same as above. Charging at 13.53 V, kill it, rapid drop, slow drop, etc, give or take a fraction of a volt. Unplugged voltage regulator and drop slowed down considerably. Plugged VR back up and drop sped back up again to .01 V/8 seconds.

Switched the meter to the blue circled DC mA scale on left. Touched posts on battery same way. Meter read .13. Moved red lead to alternator stud, black lead still on battery neg post. Meter read .13. Moved red lead to stud on starter relay on driver's side fender by battery. Meter read .13. Moved red lead to small gauge wire stud on starter. Meter read .13. Removed negative battery cable. Touched black lead to center of naked post. Red lead to alternator stud. Meter read .13. Moved black lead to unhooked ground cable. Meter read 0.00. Moved black lead back to battery post. Meter read .13.

Gotta go to work. More in a little while......
 

here are a few things that draw current even with the key off:

car stereos that have a separate Batt wire / Acc wire
this keeps the clock set and remembers your programmed stations & settings

Ign switch has a hot line always. so if there is a short in the switch it will drain the battery

Dash clocks

headlight switch has permanent hot line. so if the switch has a short it will drain the battery. or if you leave the dome lite on haha
 
In my mind If a small draw like a dome lamp or glove box lamp will kill a battery overnight, the battery is bad. In that case the fault could be in the battery itself and not in the car.
Can we assume you had the battery tested or at least looked for swelled sides, boiling cell(s), wet top ?
 
The way you appear to be using the meter for current is invalid; you have to disconnect a wire and connect the ammeter between the wire disconnected and the point to which is was connected to read current. When you put the ammeter leads directly across the battery posts, it instanly blew the fuse and the .13 mA reading is a residual reading in the meter from some internal leakage with 12v applied. Those results are totally meaningless.

When you say 'kill' the car, please confirm that you mean you turn the key to OFF and remove the key. Is this wiring stock? Year and model?

The voltage dropping from around 13v to 12.6v or so in the first several minutes after running is normal. A good battery after 'resting' for an hour or so should read in the range of 12.6 to 12.7 volts.

DRIVE the car for at least 30 minutes to get a good charge into it. Then park, disconnect one battery lead, and let it sit for 4-6 hours or overnight. Then check the battery voltage; it should be in the range stated above. If in the 11.7 to 12.4 or so, then a cell is weak and will not take a good charge. If in the range of 10.5 to 11.5 volts, then a cell is shorted and is discharging itself. This will test the battery and confrim or deny that it is the issue. OR, as suggested, take it to a store and have it tested. (But I prefer to test it myslef as above.)

Since so many people have trouble properly using ammeters, then do the test with the light in the - battery lead as described by 67Dart273 to see if you have a current drain. He puts that out as it IS simple and easy to do and does not tend to blow up meters, etc.

The fact that the voltage drop at the battery slows when you remove the VR connector with the key (presumably) OFF, that is of interest. There should be no significant draw with this connected and when the key is OFF.
 
The way you appear to be using the meter for current is invalid;
Yeah, I spent some time with a friend of mine this morning and he taught me some things. Basically, I wasn't checking anything relevant the way I was doing it. He showed me the error of my ways. He's going to spend some time with me at lunch and show me how to check really these things. I'll have an update with some REAL information after that. Sorry for the misinformation.

On another note, left the battery positive cable off last night. Hooked it back up this morning, she fired right up and drove her 40 miles to work. Checked battery voltage immediately upon parking and turning the key off and it read 13.47v. Watched it drop down to 13.41 immediately then start it's slow, 8 second, cycle back down again. When it dropped to 13.2v I removed the positive cable again. My friend and I are going to do some analysis at lunch and I'll post our findings. Sorry for all the confusion and thanks for all ya'lls help!
 
. Meter read 13.08 V but dropped rapidly down to 12.78 V and continue to drop slowly at a rate of .01 V about every 8 seconds. When it got down to 12.66 V ...

This could be considered "normal." Batteries get what is called a "surface charge" after running. A normal, healthy, fully charged lead-acid battery should read close to 12.6V after it's been sitting for a number of hours with no load (disconnected)


. Switched the meter to the blue circled DC mA scale on left. Touched posts on battery same way. Meter read .13. ...

Not legit. Please re--read my post. A CURRENT meter, (ammeter or milli-ammeter) must be in SERIES. You have most probably blown the small internal fuse that protects this circuit.
 
First off, I would like to apologize to you guys for jerking your chain due to complete and total lack of knowledge on my part. After working with my friend for a half hour, with the car, he informed me there was nothing wrong with my charging system and taught me why and how I should know. I had no drain on my battery other than what would normally be expected after charging and sitting. I realize now how ignorant I really was in the basic use of a VOM and diagnosis of an electrical system. I will study this for the future and not waste ya'lls time until I have an intelligent question to ask. #-o

Now, apparently, here was the real problem. After testing various things without the car running, we then progressed to "run" mode for additional testing. Unfortunately, the car was dead and had no current going to the starter. Everything from the battery up through the ignition module and to the ballast resistor on the firewall checked out but we kept getting random readings at the resistor. That was when he fiddled with the ignition module and noticed the "wiggle". It was held in with sheet metal screws and they were not tightened down securely. I replaced the screws with bolts/nuts and tightened securely. She fired up at first turn of the key and everything checked out fine from there.

Thank you all for your patience and your help!
 
Take it to autozone or discount they will check you battery and charging system in the car for you.

Just a side note while it is charging IE engine running at atleast 2500 RPM what isthe voltage on the Battery and at the alternator. If it is only 13.5 then it sounds like you have a charging problem.
 
Well at least that part was that easy. And cheap.

However, if the car did not crank and did not get any juice to the starter, then fixing the ignition module ground is not going to fix any issues with the starter. So..... I think you have multiple issues, and you will have to be ready to see why the starter does not work the next time it does not crank.

Chekc carefully through all your grounds to the battery, chassis, and engine block.

I would keep your voltmeter handy, and check the battery voltage after the car sits for any length of time (and BEFORE you try to crank it) and do that for several days and keep a log. In that way, you will have a record of the 'rested' battery voltage which will be excellent info to see if your battery and chargin system are good.

If you jump in the car and it just sits there when you turn the key to START, then put the voltmeter between ground and the yellow lead on the starter relay and position the meter where you can see it, and turn the key to START again. It should jump to 12 volts with the key in the START position. If good, then it is in the neutral start switch, the start relay, or the starter and wiring. If no 12v shows on the yelow lead with the key in the START position, then the issue is in the firewall connecotors, the fusible link, the igntion switch or connector, or perhaps the battery connections. That yellow lead is a good point to start with as it is about in the middle of the starter path that all has to work.

Also, if it is dead and won't crank, see if your headlights will turn on. If not, then suspect the fusible link. I would examine that anyway to to see if there are any hard of 'floppy' point in the wire indicating a fusible link failure.

IMO, don't fret too much on the initial info...we all zone out on things from time to time. And if you don't ask, you don't learn. As I am fond of saying, the only people who never make mistakes are the people who never do anything....

PS: I still can't figure out what car you have....??
 
Thanks for the info and test procedures, nm9stetham! I'll keep that handy for when/if she acts up again. She's a '74 Dart, 225 /6, A904 auto. Bought 3 Saturdays back, paid $500 and drove her 40 miles home. Dealing with a plethora of PO sins, mostly in electrical hell. Spent the 1st week just getting the lights working so I could drive her to work. The guy actually used a trailer wiring harness and 6 clip on splice connectors on the rear tail light harness. I have no idea why. Similar jury rigging on the headlight switch. After rewiring everything back together with the original wiring, reterminating, resplicing, etc, all the lights worked. Still no gauges but that's coming soon. Also had to replace the radiator due to overheating issues but she's running pretty good now. All in all, I'm pleased with her. Thanks for all the help and encouragement!
 
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