Where do I look now for current loss

[sturgeon-phish]

I have been looking for the source of a current draw when the truck is just sitting with nothing on. I measure about .2 amps when I hook my meter inline on the positive line. I went through and pulled then replaced each fuse one at a time checking the current measurement each time. The current remainded the same during this test.
Any suggestions as to what to do next?

Thanks so much
Jim

[redbird2]

by chance did you unhook the alternator possible bad diode causing draw, or unplug the ABS unit never seen one pull a draw anything is possible any other add on accessories
good luck

[sturgeon-phish]

Redbird,
Thanks for the reply. I pulled the ABS fuse; no change. I removed the alternator, had it tested (four times) and with the alternator out no change in the current draw. Any other ideas? I guess the good part is I just finished a garage addition and at least I'm inside working on it!
Thanks
Jim

[a5150nut]

Have you got a hot lead in your trailer plug for your trailer? I had to fill my connector with silicone to stop the shorts on the back side of the receiver plug.

[sturgeon-phish]

Yes I do have a hot lead to the trailer plug. I will check it out.
Please keep the ideas coming.
My guess is I will eventually find a hot lead that is going to ground somewhere between the batteries and the fuses since pulling the fuses does not effect the current draw.

I'm guessing now
Jim

[BamaChief600]

I have the same problem and cant seem to find the drain.

[sturgeon-phish]

The hot lead for the trailer pigtail comes off my aux post. I disconnected the lead at the aux post and still had the .19 amp draw. Also disconnected the trailer brake supply, same thing.
Could one of you guys measure your current draw in line in the positive lead from the battery to the cable and give me a reading please. I want to ensure I'm compairing apples to apples.

I really appreciate your help
Jim

[BamaChief600]

I am getting my draw on the Drivers side battery and no draw on the passenger battery. Ill check my trailer set up also.

[sturgeon-phish]

I am measuring on the driver's side. I did not check the other becasue I assumed it would be the same. What was your draw?
Thanks for helping with this. Maybe we can find a cure!
Jim

[BamaChief600]

My draw is .2-3

[Chief919]

I have one of these:

http://www.toolrage.com/ProdImages/ESI-306B.jpg

to be most invaluable when tracking down excess current draw.

[sturgeon-phish]

My draw is .2-3

My draw is .19 so we are in the same ballpark.

[sturgeon-phish]

I have one of these:

http://www.toolrage.com/ProdImages/ESI-306B.jpg

to be most invaluable when tracking down excess current draw.

Can you please give me some info about this?
Jim

[Chief919]

It is called a fuse buddy, you insert it in place if the fuse (the fuse gets placed on the side of the probe and is still in the curcuit so it is still protected) and it gives you a readout of how much current that circuit is using.

Google "fuse buddy" and you will find lots of sources.

[Robyn]

Have you pulled allthe fuses out at once then checked the draw?

What year is the truck?

There may be some items that are fused though remote fuses such as the trailer brake unit.

If you have any accessories like the brake controler, unhook them and see if this helps.

The early diesels 91-94 had a fuse in the junction block for the Lift pump and there certainly could be other remote fuses.

Try first by removing all the fuses at once and unhooking the brake control. Scour the rig good and yank any and all fuses.

.2 amps is very small.

The radio/clock and a few other little goodies that have memory could consume that much.

Usually when you hook up the + cable on any newer rig there is always a tiny spark.

Power to the computer?

Have you been seeing the batteries go down over a short period?

Good luck
OH BTW the little fuse buddy looks like a diagnostic dream tool.

Robyn

[JTodd]

It seems like that is a normal draw with the truck sitting. The computer takes some and the radio takes some even turned off. What problems are you having?

[sturgeon-phish]

The problem is if the truck sits for more than a few days there is not enought juice in the batteries to start the truck. I've tested the atteries and they are within spec. I've also done the fuse removal bit.
If the .19 amp draw is normal, I may be chasing a ghost and just need new bateries dispite what the batery test says.
Is the .19 amp draw within normal spec?
Thanks so much
Jim

[Chief919]

Could be batteries, could also be a starter going bad that is drawing more than normal amperage.

However, given that it only happens after sitting for a few days, my guess is bad batteries.

[JTodd]

Someone help me out here. What is the equation for battery drain? If a battery can hold approx 200 amp/hours (is this close) then your drain would be take a month to drain a single, good battery.

Next time you are going to let the truck sit for a couple days, pull the cables. See if the batteries hold a charge with nothing attached.

[WhiteTruck]

A couple of observations.
1. Normal draw should be around .020 amps.
2. You should have only one battery connected to check the truck, as an imbalance in battery condition could give you a misleading diagnosis. If your draw is normal with only one battery. It is possible for a battery to test OK, but have inadequate reserve capacity. One way to check this is to have only one connected at a time, and after it sets a few days, the one that is dead is bad!:eek:

[joe bleaux]

sturgeon-phish:

How are you measuring this excessive load? Are you measuring from the positive terminal of one battery to its ground or the block ground or the ground of the OTHER battery?

Are you measuring with an analog meter or a quality digital meter?

Joe


The problem is if the truck sits for more than a few days there is not enought juice in the batteries to start the truck. I've tested the atteries and they are within spec. I've also done the fuse removal bit.
If the .19 amp draw is normal, I may be chasing a ghost and just need new bateries dispite what the batery test says.
Is the .19 amp draw within normal spec?
Thanks so much
Jim

[sturgeon-phish]

I am measuring with a digital meter in series between the drivers side positive post and the removed positive cable.
Jim

[joe bleaux]

Whoops, I just read my question to you -ha- it would blow the fuse in your meter.

Is the other battery connected when you do this, I forgot if you said so.

Have you tried another meter?

Joe


I am measuring with a digital meter in series between the drivers side positive post and the removed positive cable.
Jim

[JohnC]

The other battery must be disconnected when you do this. To be safe, remove the negative from the other battery. Otherwise the reading is meaningless.

If you have 2 65 A-H batteries (typical) you can draw 1 amp for 130 (65x2) hours or 0.1 amp for 1300 (65x2x10) hours. 1300 hours is 54 days. Of course, after 54 days the batteries would be pretty dead. If you want to have enough left for a start, figure no more than half that, or 27 days. If you're drawing 0.2 amps that's half again, or 13 days. At that point, figure it's like starting on one of the 2 batteries, so it better be a warm day...

[sturgeon-phish]

Well I broke down and bought two new batteries. I pourposly did not run the truck today after installing the new batteries. I will be interested to see now if the truck will start tomorrow. I did notice when I removed the old batteries there was wet spots on the bottom and signs of leakage. I wonder if the battery was going to ground through the leakage?
I will post tomorrow as to the continuing saga.
Thanks again for all the input
Jim

[joe bleaux]

What a gremlin, Sturgeon. If the wet spots were from cracks in the case of the battery, I would bet money that you have found your problem on your own.

Now, take some baking soda and sprinkle on the wet spots or where the battery now sits and if it foams, you are home free unless a series of coincidences are working with Murphy.

Congrats.

Joe


Well I broke down and bought two new batteries. I pourposly did not run the truck today after installing the new batteries. I will be interested to see now if the truck will start tomorrow. I did notice when I removed the old batteries there was wet spots on the bottom and signs of leakage. I wonder if the battery was going to ground through the leakage?
I will post tomorrow as to the continuing saga.
Thanks again for all the input
Jim

[sturgeon-phish]

The new batteries seem to be doing the trick. I let the truck set for a few days and tried today and she started right up. Just for the heck of it, I am going to take the old batteries to have them tested again out of the truck.
But, it seems the problem is solved. Thanks to everyone who provided help and sympathy
Jim

[TAG]

.2 amps is high. Its the equivalent of 1 194 bulb staying on. Every car or truck i have had to test for a draw in the last 10 years read 0 amps when everything is working properly. Most will show a half to one amp initially until all circuits time out, then goes to zero. Pcm & radio memory draw doesnt show on a meter reading to tenths. I am guessing the new batteries are masking the problem for now but the constant draw will shorten their life. The majority of the draws i find in my shop are either the alternator ( diode) or something to do with dome lights. Alternator diodes are usually more than 2 tenths, some kind of courtesy lights are usually the problem on that size draw.

[sturgeon-phish]

Tag,
You may be correct and I will continue to verify nothing is ON drawing the current.
Thanks
Jim

[HiwayDiesel]

Weee this is fun. New adoptee to my fleet* is (occasionally) killing two new batteries dead overnight. I have just started diagnosing this problem tonight and I shall post my findings when we kill this gremlin. I wish I had a Fuse Buddy for DMM in hand, but will be adding one soon.

Based on some of y'alls post, I am going to swap out the alternator and see what happens overnight. If that doesn't work, then we begin the process of elimination....

*1997 C3500 C&C 6.5TD waiting for the usual mod....remote Dtech PMD

[Kenneth]

In my automotive electrical class and book it says that 20-40 mA (0.2-0.4 amps) is normal draw for up to an hour after the ignition switch is turned off. This is the normal electrical draw used for the accessories (radio clock) and for the computer to run "administrative" tasks.

I'm glad it looks like you solved your problem.