Pretty much what the title says. How can I track down what is draining my battery? Is there a way to see if a circuit is drawing power when the truck is turned off, with an ohm meter at one of the junctions or something? I'm thinking that there might be a short or something, that is also causing my cluster problems, but I have no idea where to begin looking.

 

You need an multimeter and then you disconnect the positive battery cable and take the meter probes, one on the postive post of the battery and the other on the cable end itself. You will have to pull the fuses one by one and see if when you pull one if the voltage changes, you will know if you find the problem or not. Good Luck!

 

You can to the same thing with a test light. Connect it between the batt and negative cable.
pull fuses until the light goes out.

 

The proper way is with an amp clamp, like the Fluke mini clamp meters, on the negative battery cable..2- .5 amp draw with everything turned off is acceptable for KAMon the PCM, SKISand the radio. Any more than that, you start pulling fuses until you find the circuit that is drawing. Be sure that you allow time for interior lights to go off before you start chasing if you've had the door open.

In my experience, draws are usually stuff that has been added (radios, amplifiers, remote start systems, nav systems, etc), a faulty door/hood/trunk lamp switch or a brake lamp switch that has been damaged, worn or is improperly adjusted.

 

How fast does it take for your battery to drain? Is it a new battery or old battery? The reason I ask... is if it is a new battery in good condition... there has to be a pretty good draw to kill it overnight... Just trying to estimate how big of a current draw you have.

Anyway... here is how I would do it...

Usevolt meter... and set it to the current measurment. Then, pull a fuse. Now, put the probe on the connectors where you just took out the fuse. Read the current draw. You should be able to isolate what fused connection is drawing the power. Replace the fuse and move to the next... You shoudl find it... There may be some small current draw on some of the fused lines. But anything over 200mA would make me suspicious.

You should be able to do the same thing with the negative battery cable (assuming there isn't a HUGE amp draw through there). But, you can also get a cheap clamp on meter at Harbor Freight (http://www.harborfreight.com/cpi/cta...emnumber=96308).

Good luck,
Cartman

 

I believe I have an entirely dead battery. I went out last night with a jump starter, but it never would show a connection when I hooked it up to the battery posts. After checking all of my grounds again and again, and spending a few hours doing so, I finally decided I would just try jumpstarting it from my Ramcharger. Well, that battery had went down enough from not being started that I couldn't crank my Ramcharger. So just for kicks, I pulled the Ramcharger battery out and hooked it up in my 98 Ram, and voila, the jump starter showed a connection. Even then, I didn't have enough power to start the truck (as my jump starter wasn't fully charged), but I know for sure it is the battery and not the truck. Maybe when I can get a fully good battery on the Ram, my instrument cluster will work properly.

Aside from that, I did find both ends of the remote power for the previous owner's amplifier, and the ground cable, and made sure they weren't touching anything. Surprisingly, when I had the radio pulled out a week ago, all of the original harness wires looked to be intact, so I guess they used an adapter harness for the cd player they had in.

If I continue to have battery drain problems after putting on a good battery, I will definitely get a clamp-on amp meter. Aside from this truck, I have another vehicle with this problem, and I know it isn't the battery.

 

I have an 04 1500 Ram that drains the battery. I put in a new battery and a couple of days later its dead. I found the drain in the fuse that runs my radio. I have since then pulled that fuse and been driving around without a radio for months. Someone out there is bound to know what causes this.

 

Do you have an aftermarket stereo? Do you have any additional amps wired up? My guess is that the remote turn on lead (usually the blue wire) that goes to the amp is wired directly to 12V. This would cause your amps to remain on all the time and drain the battery.

My guess (from the limited information in your post) is that the blue wire is tied to the 12V supply for your head unit... When you pull the fuse, that cuts power to your head unit (and the amps if the remote turn on lead is connect to 12V there).

Cartman

 

Bumping an old thread here. Im having the same problem with my '97 1500 4x4. I hooked my volt meter to the negative battery post and negative cable, it read that there was 12v there. I proceded to pull fuses one by one and even pulled all the ones inside the cab, pulled all the relays one by one too, still read 12v, when i unhooked the positive cable that runs into the fuse box, it read 0v.

My question is this, what is it supposed to read? By disconnecting the positive cable that only goes into the fuse box, does that kill the power for the whole truck, and i didnt get anywhere by doing such? Or is there a short in my box between the fuses and the battery? Or am i looking in the wrong direction period?

 

" I hooked my volt meter to the negative battery post and negative cable, it read that there was 12v there".


You might do better with a test light than with a voltmeter. You might get a reading of 12 volts on some circuits that's the result of a draw of a few milliamps, which could be normal and not enough to drain the battery. If there's a big drain on one circuit it would look the same to the voltmeter as a tiny drain; 12 volts.

If you use a test light, and you do have a significant drain on a particular circuit, the light should be fairly bright when you put it between the negative post and the negative cable, and should dim or go out when you remove the fuse for that circuit.

Bottom line, you want to be detecting current draw, not just voltage.

***

This guy put it a different way in this thread:

"The proper way is with an amp clamp, like the Fluke mini clamp meters, on the negative battery cable... .2 - .5 amp draw with everything turned off is acceptable"

If you did have a bigger draw than that, the amp meter would go way down when you pulled the fuse on the bad circuit. Again, amp draw, not just voltage.