So my battery went dead after I just a got a nice dual terminal battery about a year ago. I figured I'd test for parasitic draw on the battery. It's my first time doing this so I youtube'd/forumed everything before attempting. So I did these steps:

1. Disconnected the (-) terminal, put the multimeter in DC 10A mode and placed the test leads between the (-) post on the battery and the (-) wire I just disconnected. Result was 2-3 amps.

2. Disconnected CB radio, KC lights, and Mopar remote start wiring from the (+) terminal and retested. Still got a 2-3 amp reading.

So is there any obvious reason for the draw? Seems like this kind of draw would kill my battery quicker than a year. Doors were closed, everything was off inside the Jeep. Alternator tested fine as well. I suppose next I'll start testing fuses unless someone has a reason for this kind of draw.

Cheers to replies.

 

Great job on the test! I've had this problem in RVs. Pull fuses one at a time until the draw goes away. Then search that circuit for the problem.

Seems this is probably a new problem. 2-3 amps will kill a battery in a day or two. 2 amps an hour for 48 hours is 96 amps, 3 amps is 144. The battery might say 800 amps of cold cranking power, but there is only about 100 to 150 amps stored in there.

 

After getting ready to do the test you have to make sure the vehicle has been sitting for thirty minutes, sometimes forty-five minutes for all the modules to go to sleep. After that you should only see .050 max on the meter or you have a draw. You should have it setup so you have access to the fuse box without disturbing any doors or anything that would turn on a light or module. That way you will be able to pull out fuses one at a time until the draw goes away if you one. Any fuse that you remove trying to find the draw must remain out until you have found the draw or you will wake up a module and then you won't be able to continue the test.

 

I was wondering if something (a module) was on a timer that I needed to wait to go off. Thanks for the info. Anything I should do except wait that long before I start pulling fuses?

 

I normally have a large gage jumper bypassing my meter until that time has elapsed. That way you don't have to have the meter turned on or worry about watching it all that time. Another benefit to having a jumper wire installed first is that once you put the meter in circuit as well it is only carrying half the load until you disconnect the jumper, you need to make sure you can remove one end of the jumper without disturbing the circuit that the meter is making. Anyway as you install the meter look at what it is reading and if you notice that it is carrying over 5 amps and it is a 10 amp meter then DO NOT REMOVE THE JUMPER.

Remember with the jumper installed the meter is carrying only half the load after you install it. That way you get a heads up of what the circuit is doing so you don't blow the fuse in your meter. Sound like you have a pretty good idea of how to hook it up just use that jumper until the time has elapsed for the modules to go to sleep and someday it just might save you the trouble of having to replace your fuse in the meter.

I haven't had to do this test in a Jeeep. In Fords which I work on it is usually the radio, gem module (now days callled smart juntion box "fuse box"), and the 4x4 module that are the most common failures resulting in excessive draw. I don't believe we have a 4x4 module since we use a lever instead of a switch to engage 4x4 so you can probably rule that one out.

It would probably be good to have the owners manual handy to identify which fuse you are pulling. It would be even better if you had the wiring diagram book since it normally says which fuse is hot even when the key is off. That way you could save time by not having to pull a fuse that isn't even powered up with the key off.

Anyway good luck with your trouble shooting and think about that jumper to save your meter.