electrical help (drain on system)

[desertrat67]

I have this to work with:

If it passes, pull the positive cable and you should be able to test amp draw with everything off. Most voltmeters will do up to 10 amps with an internal fuse, and that should show any draw. If there is a draw of more than 1 amp, start pulling fuses one at a time until you isolate where the draw stops, that is the circuit with the issue.

but the first time I went to test for draw, I blew the 10A fuse in the multimeter.

I have a 90 sub with a 6.2 diesel, so that means 2 batteries in series.

What needs to be disconnected and where do I test for draw?

My first test was with the right battery positive disconnected and the jumper running from it to the left battery disconnected as well. I touched both terminals on the right battery and zzzaaappp! Fuse blown.

Enclosed is pictures of the batteries and terminal setup. Pic one is right battery and two is left battery. Right battery Negative post is main ground to alternator bracket; Pos term is power to starter and return from alternator and jumper to left battery. Left battery positive is only connected to other battery and winch. Negative is grounded to AC bracket and also the negative lead for the winch.

 

[sweetk30]

dont have door open unless you pull the wire for door jamb button or dome light can pop fuse.

also check for working hood light if so unplug it.

then better to use a test light to get close on the draw. then when you think you got it swap to multi meter.

test light bulbs cheeper than the fuses.

all aftermarket stuff like radio and crap wired in correct or can draw down crazy.

 

[desertrat67]

I mainly need instruction on where to test? I currently have every fuse pulled and will put them back in one by one until the draw appears, but I think I am testing the wrong location.

 

[sweetk30]

sorry. install all fuses. then pull 1 buy 1 till draw goes away is the way i was always told.

 

[desertrat67]

Frustrated.

I installed all fuses and there is no draw(if I am checking at proper location).


Is this the proper procedure?:

The left battery is still connected to the right and the left and right grounds are connected. The positive cable on the right battery(goes to starter) is disconnected. I am checking for draw between the disconnected positive cable and the connected ground of the right battery. All fuses back in and show no draw.

Just for reference, one battery is brand new as of yesterday, the other was slow charged yesterday and is actually only 4 months old or so. The alternator was tested in Mar and is good. If I let the truck sit for 3 days it won't crank. I just disconnected the winch in case that was the problem, but did a continuity check on its cables and could not detect a short.

 

[bp71k5]

You take just one positive battery cable off. Then put the black multimeter probe on the positive battery post and the other probe on the disconnected bat cable. Make sure the meter is on the amp setting and not voltage.


-Brian

 

[4X4HIGH]

I have this to work with:



but the first time I went to test for draw, I blew the 10A fuse in the multimeter.

I have a 90 sub with a 6.2 diesel, so that means 2 batteries in series.

What needs to be disconnected and where do I test for draw?

My first test was with the right battery positive disconnected and the jumper running from it to the left battery disconnected as well. I touched both terminals on the right battery and zzzaaappp! Fuse blown.

Enclosed is pictures of the batteries and terminal setup. Pic one is right battery and two is left battery. Right battery Negative post is main ground to alternator bracket; Pos term is power to starter and return from alternator and jumper to left battery. Left battery positive is only connected to other battery and winch. Negative is grounded to AC bracket and also the negative lead for the winch.

Lets get something straight here, two 12 volt batteries hooked in series will be 24 volts and the way you said the batteries are hooked up is not in series. A series system would be the positive from one battery to the negative on the other then the first battery's negative would be the main ground with the other battery's positive being the 24 volt.

 

[desertrat67]

I guess i misunderstood and used the wrong phrase. I thought series was hooked straight in line, while parallel put pos to pos and neg to neg. Will fix original statement.

 

[desertrat67]

You take just one positive battery cable off. Then put the black multimeter probe on the positive battery post and the other probe on the disconnected bat cable. Make sure the meter is on the amp setting and not voltage.


-Brian

Thank you.

 

[desertrat67]

Nothing. I did disconnect the winch the other day, so that may have been it. I will see if the batteries drain again. If they do, it is going in for professional help.

Thanks for the help guys.

 

[Fordum]

I guess i misunderstood and used the wrong phrase. I thought series was hooked straight in line, while parallel put pos to pos and neg to neg. Will fix original statement.

Well, that statement was right. Remember, if you hook the negatives to different parts of the block, that is the same as hooking them together.
So, if you hook the negs that way, and then hook the positives together, that is parallel

I would not necessarily run to other professional help too fast. Remember, you've got some of the best professional help going right here.
No, not talking about me. Although I'm pretty darn good when it comes to electrical and I do do it for a living.....

If you have the two positives hooked together, and have disconnected them from the truck and put your meter on amps between the two positive cables and the truck with no results, don't give up.

Consider anywhere a light could be on without your knowing it. If you have a glove box light, thats a good one.

But, there is one other thing that gets overlooked or not considered many times.
A bad battery will drain both batteries.
If you are going to let it sit for a while, make sure both batteries are charged. Disconnect them from each other, and measure across each one.
Making sure to remember to switch back to volts before you do.
Gotten in a hurry way too many times myself.
Note the voltage on each battery.
After it sits for a while, recheck them.
If the one still hooked to the truck is dead, it either means you still have a drain, or its a bad battery.
If the one by its self is dead, its got an internal short and is what is killing both batteries.

 

[bp71k5]

Making sure to remember to switch back to volts before you do.
Gotten in a hurry way too many times myself.

x100. Don't forget that! It took about 2 seconds before I noticed how hot my multimeter wires were getting after I forgot to switch back.

Also, with dual batteries, you may not be registering anything on the meter if the second battery is still connected. The drain will be spread in half which might be too low for the meter to register (depending on which scale you chose to use).


-Brian

 

[folkenheath]

Frustrated.

I installed all fuses and there is no draw(if I am checking at proper location).


Is this the proper procedure?:

The left battery is still connected to the right and the left and right grounds are connected. The positive cable on the right battery(goes to starter) is disconnected. I am checking for draw between the disconnected positive cable and the connected ground of the right battery. All fuses back in and show no draw.

Just for reference, one battery is brand new as of yesterday, the other was slow charged yesterday and is actually only 4 months old or so. The alternator was tested in Mar and is good. If I let the truck sit for 3 days it won't crank. I just disconnected the winch in case that was the problem, but did a continuity check on its cables and could not detect a short.

I have found it helps to have a short "jumper" cable to hook in parallel to the multimeter. Sometimes when you first touch the multimeter to the battery and cable it will blow the fuse from the initial jolt. If you have a jumper wire hooked up to the cable first, then hook up the multimeter in parallel, then disconnect the jumper, you remove the jolt from the multimeter. Keep in mind your miltimeter should have a large and small scale for the ammeter that will probably require the positive cable be plugged into a different point. I thin my larger one is 20A.

Also, you will need to disconnect both battery grounds and just test the drain using one of them for now. (ground wire to ground terminal) You can also use positive to positive, either way will complete the circuit and you can test the vehicle. If you don't find the problem then maybe have your batteries tested.

 

[desertrat67]

All of my testing was done with my winch disconnected. Guess what? It has lasted several days with no sign of drain.

Think I found the problem.