Diagnosing parasitic drain

Truck is always dying. I put a new optima redtop in after I thought it was the old battery and it runs great when it's driving. However, if I don't drive it for 4 days it is dead.

I took the optima redtop in to get it fully charged and they said the battery was no good so they warrantied it and I got a new one. Don't want to mess up this battery now!

I've tested the in line method with 3 different voltmeters (2 of them Fluke, and one brand new one). Always black on COM and red on 10 amps on voltmeter on the 10 DC position. Red on the negative battery terminal and black on the clamp.

I've also done the alligator clamp way with unhooking the negative - attach alligator clamps from the clamp to the terminal - wait until car is asleep, then attach voltmeter and remove alligator clamps and it reads nothing.

It always reads 0.00. Anyone know why? Is the car really not pulling anything when its off?
I tested the voltage of the battery - 12.58 v yesterday and tested it today at the same time to see if drain is really happening at it reads 12.48 today so it must be draining still.

It is a 2013 4runner (should not be applicable to the problem) and is 100% stock with no accessories.

Am I being dumb with how to use a voltmeter? I have no electrical background so that is always an answer

Thanks!

 

Does your DVM have a mAmp setting? The 10A setting might not be able to resolve the drain which may well be on the order of 50mAmps or less.

 

10 amps is too high and it won’t pick that up. Set on a smaller scale

 

I like the Humble Mechanic's YouTube channel, this is his approach to finding a current draw, and thought it may help you find what's causing your battery to die so soon.

https://www.youtube.com/watch?v=lRcj1fQcWwU

 

A Fluke will quite happily read m amps on the 10amp scale; I do it all the time. If you've got 0.00, I think you may have blown a fuse; the ONLY time I've ever seen a constant 0.00 on a Fluke measuring current is when I f***ed up and blow the current fuse.

 

thanks guys. So my dial should be set at the 2000 then?


I tired the fuse way too! Just if it was a pulse every minute or so I wasn’t able to pick it up with a few seconds on each one

 

Here is the fluke setting

 

Depends on what Fluke you buy

 

Unrelated to the voltmeter but do you know if the vehicle has any kind of dealer installed tracking device installed? My uncle was having this similar issue with a old Jeep he had and when I was working on the stereo I found a very Unusual looking cable and followed it to some weird looking 90’s LoJack unit with a battery backup. Removed it and problem went away. Then started even after it sitting for weeks.

 

I can check! Don’t think so though.
I sold my pristine 2010 trail with 64k miles and bought this 2013 trail with 175k miles a year ago. It started dying on me in October so pretty recent and hasn’t been since I bought it. I do live in tucson az so shouldn’t be any cold weather affecting it. Not sure what would’ve changed

 

On the red meter you'll want it on the 200 probably. The Fluke should be good as-is.

 

The car is sitting for an hour with two alligator clamps between the negative clamp and battery terminal. I’ll try again in a bit. I’ll put the the red probe on the negative clamp and the black probe on the terminal and then disconnect the alligator clamps. Hopefully it reads something.

 

Ok so the fluke is working for both connections - reads this number while beeping and saying lead (so according the YouTube that means it’s good)
I’ll test my truck with this one since I know this one is fine

 

Actually when I just place the leads in instead of holding them straight it says OL so maybe the fuses are blown?

 

I got the first numbers by holding it straight in like at 1:49 in this video. If placed in I do not get that 2.1 number. However, it does beep and say OL which the video says the fuse is good then
https://www.youtube.com/watch?v=I6XCDj7m2LA

 

FWIW, the Fluke 87 is the better DMM.

Based on my experience, the only way to measure current (Amp) the meter needs to be connected in series. Your connection between the Neg battery terminal and the cable should be good. Start with the Fluke dial set at mA/A range with the red lead in the "A" port and the black lead on the COM port. If no reading, then shift the red lead to the "mA/microA" port.

The Fluke 87 is an Auto-Ranging meter. It will display the correct units.

This connection will check the entire truck for parasitic drain. Trust me, it has a parasitic drain. How big and which circuit leading to which device is a different exercise.


BTW, your method (pictures) for checking the leads is completely wrong. To check resistance/continuity one connection needs to be on the COM port, the other connection needs to be in the V/ohm/diode port. You may want to spend a little time with the Fluke Operating manual.

 

when trouble shooting there are some basic steps
1- isolate OEM wiring harness from ANY / ALL add wiring & accessories

then measure for ANY HI-Resistant grounds & opens
( people always say ‘ short ‘ circuits ‘..........................sometimes there are worn insulation sometimes crosses )

when accessorizing there are some basic steps
a- never cut orig vehicle wiring
b- set up power feed on a secondary connection so that the OEM harness can be isolated

measuring voltage on batt tells U little
losing a tenth of a volt tells U nothing
disconnect All accessories.......................some are NEVER ‘ OFF ‘

the vehicle reacts to horn ......alarms ..... brake lites etc even tho the ignition is OFF

even tho its been sitting all day ( or nite )

disconnect the Pos Batt post completely .......put the fluke in series
One lead on the Pos batt harness ........the other on the Pos Batt post

voltage or amperage if everything is correct
there should not be much of a draw....................some maybe as most vehicles nowadays
ALWAYS have something running no matter what

Fluke set on resistance
test the ALL disconnected accessories Pos lead on every wire...................Neg lead against frame ground then against Neg Batt Post

be deliberate............

 

Thanks. Yeah that is the method I have been using. I will try it again here in a moment and take some pics as well.

Yeah I agree it does have parasitic drain

I wasn't checking the leads - I was checking if the fuses were blown (following the Fluke video). The leads are fine and read .2 ohm. Also don't have the manual - borrowing this meter from our boat lab

 

nada

 

I'm not confident your connections for the meter are solid.

The alligator clip will fit on the end of the probe.

Try the following.

Reconnect the Battery Neg cable to the battery. Remove the Battery Pos Cable, jump the meter between the + post and the + cable. Set the meter as before use the "A" port. Go into the truck, turn everything off, turn the key to the ON position. DO NOT START THE TRUCK. What is the meter reading?

Next turn on the dome light....What is the meter reading?

Now, turn OFF the key, close door and lock the truck. What is the meter reading?

Go away for 30 minutes, leave the meter connected and turned ON. What is the meter reading?