Originally Posted by John D in CT

" 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.

Originally Posted by jadanpuett

I have a 1989 w150, it doesnt have a fuse box under the hood. I just got a brand new battery. Everytime i go to drive my truck i have to jump it off. The battery will last about 2 days and then its drained again so how would i find whats drainging it?

Originally Posted by Acrylicophobia

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.

Originally Posted by rdbradleyjr

So I have the same problem but in reading this I think mine may be more than a fuse. On Friday my truck would not start. I took my alternator and battery up to Autozone to have them checked. The alternator tested ok but the battery was too dead to tell if it was faulty. So I replaced the battery and re-installed everything. The truck started up just fine, no problems whatsoever. Sunday afternoon I went to drive it and it was dead. And I mean dead, dead. Not a light, nothing. I didn't even drive the thing from the time I replaced the battery to Sunday when I tried to start it. I don't have anything after market on the truck. It's the original tape deck. What the heck can drain a brand new battery between Friday afternoon and Sunday afternoon?

Originally Posted by volaredon

no the fuse does not cause the draw. What is "after" the fuse on that circuit does.
sure your big battery cables are good? They corrode from inside out and cause all sorts of resistance to flow. Check your grounds to be sure they are solid and have full continuity.