Need help using a Multimeter

[no_pulse]

It seems something is drawing a current and is draining my battery. After a day, my battery is completely drained. This has been happening for over a year now, I'd like to find out what is draining the battery when I shut off my truck.
I went and got my battery replaced the other day since its still under warranty. And before I put it in and leave it hooked up, I want to find the problem.
I've never used a Multimeter before and I was hoping someone could help. I read on some sites that you disconnect the negative battery cable and then others sites say to disconnect the positive. I'm a bit confused.
Here is the Multimeter that I bought. http://www.equus.com/product_info.ph...tegory_id=1_60



If someone could tell me what I set the multimeter dial to and where I use the diodes.

[CatDaddy52]

Ammeter looks like it's at the 7-8 o'clock position. Blue "DC mA" will measure small current draws & the yellow "DC 10A" will measure larger draws.
Doesn't matter if you disconnect pos or neg, just do one or the other & connect the probes. Start pulling fuses until you see the draw change....that will be the ckt with the issue.
Note: Normal parasitic loss should be less than ~30mA. Make sure any/all modules have "timed-out" before measuring losses.

[nd4spd18]

Also note the 3 connectors on the meter. Plug the red probe into the standard one when using the DCma setting and into the DC10A connector when using that setting. Black probe to the COM connector.

Start with the DC10A setting and then switch the the other one if you dont get a measurable reading. Reason is, if the draw is more than the lower setting can take it will blow the fuse in the meter.

Just pull one of the battery terminals and connect the probes in-line to the battery. One more note, DON'T try to start the truck or turn anything on with the meter in-line like that, it will blow up the meter at the very least. I would even pull the dome light fuse before starting this so you dont have that drawing power if you open a door.

BTW looks like a pretty nice auto ranging meter you chose there.

[CatDaddy52]

^^^Good points!!

[lownoma1995]

if your trying to find the draw you have to put the multi meter to ameters and connect it in series but becareful if the circut is running more then 10 amps you are going to blow ur multi meter and always leave black connected in the com spot you never move it

[comics22]

hmm i should make a simple how too for doing simple tests with a multimeter...

but what has been mentioned is what to do.

do you have anything electrically different from factory? (headunit, subs, amp, rewired lights, trailer harness, etc)

do all the lights and electrical crap work when thier supposed to work on the truck? (dome lights turn on and off, etc) does your glovebox light turn off with the door closed?

[no_pulse]

Quote: Originally Posted by comics22

do you have anything electrically different from factory? (headunit, subs, amp, rewired lights, trailer harness, etc)

do all the lights and electrical crap work when thier supposed to work on the truck? (dome lights turn on and off, etc) does your glovebox light turn off with the door closed?

What is not factory is, my Viper alarm, sound system (3 subs, 2 amps), tach, fog lights and trailer harness.

Everything seems to work fine as far as I know. The headlights come on when I press the switch, dome lights come on when I open the doors and turn off when I close them. Same thing with the glove box. The only thing that doesn't seem to work is the cigarette lighter. Not that it matters, I don't smoke. I bought a solar powered battery maintainer that plugs into the cigarette lighter but I guess that's why the battery maintainer doesn't work, since the lighter doesn't seem to work.

Could it be a bad battery connector that could case a drain? Years ago the auto club came out to replace my battery when I was stuck on the road. Turns out my battery leaked all over the positive cable and the guy from the auto club had to cut the positive battery cable to remove the battery. And then he did a hack job of replacing the positive battery connector.

[comics22]

it COULD be (ive seen some weird shit when it comes to corrosion) bad connector but try pulling the main power fuse to your amps (hence cutting off the power to the amps).

my friends amp still worked but never seemed to shut off, so his battery drained in like 2 days of sitting. disconnected the amp and walla! instant fix

[alvisoroadsters]

what was your amp draw?