i have what appears to be a pretty good parasitic draw on my truck. i just replaced my 18 month old batteries that would die within one day of being left alone. i did have them tested and they failed.
now i upgraded to some large agm deep cycle batteries and they are lasting about 4-5 days before becoming completely drained.

i went to my work and borrowed a co-workers mac multi-meter and performed a normal parasitic draw test. i disconnected all ground sources, put the multi-meter in series between the battery ground terminal and the ground wire. I even double checked the procedure in the mac operation book. i repeated this process for both batteries and my auxiliary fuse box.

on the mA setting it was reading next to zero amperage draw, 0.02 - 0.03 and for some reason it never changed even when disconnected. i am guessing that the multi-meter may not be reading correctly.

is there any way to test parasitic draw with a multi-meter that does not test amperage, mine can only test AC amperage, continuity, ohms and voltage.

 

Hows old is the Alt and what amps is it putting out?

 

What does the charging voltage get up to on the meter? I'm with him ^^^^ it may be a prob with the alternator. If its not charging, excellent batteries could keep it going a few days and then too weak....

 

\I've never seen a multi-meter that didn't test both ac or dc volts and amps. When hooking a meter up in series to test a current draw I suggest going to the 10 amp. scale. I've seen many a meter cooked on the ma scale. Even on a Fluke meter the fuse wasn't quick enough.

 

i neglected to tell that my charging system is in immaculate shape. i have a brand new 185 amp DC alternator, along with upgraded "big 3", battery grounds are good, heavy gauge charge wire, and heavy gauge inter-battery wires.
my charging system can get up to 14.4 volts as seen from my edge or my power inverter while driving.

my voltmeter is rather old but still seems to function fine. it has an AC amp clamp only.
the mac meter is used i only used on mA, maybe this was my problem but it didnt seem to blow a fuse or anything?
when i say that my batteries die after 4-5 days i mean if i leave it and dont run the engine like i did this last week. it should never die that fast with everything turned off and new batteries.

 

Do a 6.0 forum search for parasitic draw. There are a couple of pretty good discussions about it and the proper way to check for it.

 

What brand of Batteries did you get? and did you replaced both at the same time? is there any trailer brake system or cell charger anything left on glove box lite?

 

I'm not sure what all was disconnected but this could be "hiding" the draw if you disconnected a bunch of stuff. You really want to disturb as few connections as possible. Just disconnect either cable from one of the batteries - doesn't matter which one (+ or -). Go to the other battery (it's now powering everything) pull a cable - again, either one. Connect the meter between the cable end and the battery post. Make sure it a good connection, vise grips work well on the post but don't squeeze the post too hard. Meter to the 10A setting. It should read down to 3 decimal places (mA) plenty low enough for this check.


COMPONENT TESTS
Battery - Drain Tests
NOTE: No production vehicle should have more than a 50 mA (0.050 amp) continuous draw.
Check for current drains on the battery in excess of 50 milliamps (0.050 amp) with all the electrical accessories off and the vehicle at rest. Current drains can be tested with the following procedure:
WARNING: Do not attempt this test on a lead-acid battery that has recently been recharged. Explosive gases can cause personal injury.
CAUTION: To prevent damage to the meter, do not crank the engine or operate accessories that draw more than 10A .
NOTE:
Many modules draw 10 mA (0.010 amp) or more continuously.
Use an in-line ammeter between the battery positive or negative post and its respective cable.
Typically, a drain of approximately one amp can be attributed to an engine compartment lamp, glove compartment lamp, or luggage compartment lamp staying on continually. Other component failures or wiring shorts may be located by selectively pulling fuses to pinpoint the location of the current drain. When the current drain is found, the meter reading will fall to an acceptable level. If the drain is still not located after checking all the fuses, it may be due to the generator.
To accurately test the drain on a battery, an in-line digital ammeter must be used. Use of a test lamp or voltmeter is not an accurate method due to the number of electronic modules.
Make sure the junction box/fuse panels are accessible without turning on interior and underhood lights.
Drive the vehicle at least five minutes and over 30 mph to turn on and exercise vehicle systems.
Allow the vehicle to sit with the key off for at least 40 minutes to allow modules to time out/power down.
Connect a fused jumper wire between the negative battery cable and the negative battery post to prevent modules from resetting and to catch capacitive drains.

 

both batteries replaced at the same time, i would never leave a weaker battery in, that puts extra stress on the good battery. they are agm deep cycle marine batteries.

when i did the testing i removed the ground cables from both batteries, which will force the current to ground through the meter that is inline between the ground clamp and terminal. I also disconnected the ground wire on my auxiliary fuse/distribution block under the dash right beside the main fuse box. i tested my auxiliary fuse box the same way i tested the batteries to see if my accessories i have installed have been the cause. all of my accessories are either ignition switched, radio switched, or have their own switch.

i am really starting to think the fuse in the meter blew or it wasnt reading correctly. there should be a slight draw simply due to all of the modules that didnt have time to "go to sleep" as i tested this after driving to my shop. i will try the tests again tomorrow after work and will ensure the meter is working properly

 

Here is a goof Youtube video on this topic.


Sean

 

Do you have an aftermarket stereo? Alarm? Remote start? My cousins 05 6.0 had a parasitic draw and it was his ****ty glow shift gauges. He unhooked them and problem solved. Idk how the edge insight gauge works? It just plug into main computer or something?

 

If it did the odds are that, that circuit in your meter is dead. Don't ask me how I know!

 

Been there done that.

30 Amps on a 10 Amp shunt.............


Sean

 

haha i have all of those!
my glowshift gauges are wired through an ignition tapped relay and only come on with the key, same with my underhood led since i dont have a switch, i do have a rather large stereo system with 2 amplifiers and my deck is wired so it comes on when i turn it on not when the ignition is on but that shouldnt be a problem. i also have a viper security system/remote start/gps tracking system. i also have a power inverter hard wired to my auxiliary fuse box but that has an on/off switch on it too.

 

haha i knew you had all that stuff. Not really haha. Well then I got nothin else to add haha. I run my nav unit on a main power switch since when i cycle my glowplugs my stereo comes on then when I go to start it it shuts off. Im thinkin thats hard on nav units.