BATTERY DRAINS OVER NIGHT

[JIM Spanglo]

all of a sudden my battery drains over night, I thought ok it is an old one so i went and got a new one the day of the snow storm. I go out to go to work and the damn thing drained..So then i started checking fuses, i took them out one by one while holding a tester onto batt...before removing any fuses it was going down .01..IE: 14.6-14.5 and so on. Well after i removed the radio amp fuse it stayed solid .....great i found it....nope..still does it..any recommendations

 

[Scottydoggs]

with your tester probe each fuse key off. only a few should have power. check both fuse boxes.

 

[OR VietVet]

You are on the right track with the DVOM. If the battery gets drained enough, even if new, can damage it but if only once or twice, I would think it is ok. Any recent work done? Don't forget the relay fuse box under the hood.

 

[Fless]

Tell us a little about your truck: year, engine, etc.

Pulling fuses is counterproductive. Use the voltage drop method across the fuse test points. There are many good YouTubes for parasitic draw; here's one from Eric at South Main Auto (he has more and so do others):

 

[SnowDrifter]

Anywhere near you that rents out thermal cameras?

Or if you're in the Seattle area, you're welcome to use mine.

IMO, thermal cam is by far the best and fastest way to chase a parasitic draw. Turn everything off, hook up a battery charger to keep stuff energized, give everything time to cool / equalize on temperature, then point around and look for the hot spot. Takes ya all of 2 mins to see what's stuck on. Relays and/or interior items will be warm. Couple degrees, not much to see if you started pointing a temperature gun at it. But it sticks out like a sore thumb on a thermal image.


I've heard that the gauge cluster can be a common source on these rigs.

Also check obvious stuff if you've not done so already. Or hell, even if you have, never hurts to verify
- Interior lights
- under hood light if equipped
- doors are closed
- that the doors register they're closed
- radio
- transmission in park
- ignition is indeed off
- headlights/running lights are off
- nothing plugged into the OBD port
- nothing plugged into the 12v interior plugs

 

[Fless]

I'm not sure what rig we're talking about; would be nice to know for some targeted suggestions. Maybe it's a secret.

For example, the Auto HVAC controls in the 2003-2006 NBS models can take 4 to 5 hours to go to sleep. If one didn't know that, it might be diagnosed as defective.

 

[MassHoe04]

Fuses only blow when current exceeds the limit of the fuse protecting any given circuit. I agree, pulling em to see if any are bad is probably not going to help. A parasitic draw might not ever blow a fuse.
I had a bad brake light switch kill my battery once. Brake lights stuck on. With the way I parked and exited the vehicle, I never noticed the brake lamps were still lit up. Not enough current to blow a fuse, but certainly a big enough draw to drain the battery by morning.

As mentioned by @SnowDrifter, take a good look all over to see if anything jumps out as the possible cause. Maybe you'll be lucky enough to catch something visually...

Good luck!

 

[rockola1971]

For anyone not trained to use a multimeter or know how to interpret what its values shown are telling you..... The first goto should be the BCM fuse. Pull it when you park the vehicle for the night. The next day stick it back in and see if your battery is dead or not by starting vehicle. If it aint dead then you likely have the stereotypical bad ground which causes the BCM not to goto sleep when you leave the vehicle which runs the battery down overnight. You could also have anything from a bad glove compartment switch which leaves the light on but you cant see it because the glove compartment is closed or even a shorted amplifier (at the speaker(s) for the premium sound package owners like the Bose models.
So If BCM fuse doesnt seem to be the cause, then start over for the next night (after charginf battery up) and pull the Radio fuse and try there.

 

[bigdog9191999]

sounds like your on the right track to try and find it. years ago i had a draw in my car that ended up being something bad in the fuse box . that one took quite a bit to find, once i swapped it, it was all good.

good luck on this one.

 

[corvette744]

Old school get a test light remove battery cable-hook end of test light to cable touch the other end to battery were you took off cable.Pull each fuse one at a time until test light goes out.Problem circuit will show it self very quick then you have to track down what in that circuit is drawing your battery down not hard to do.