Battery draining overnight, can't find the draw anywhere.

[lvin4jc]

My battery drains overnight, every night. But if I unhook the battery and let the truck sit for a week when I hook it back up it starts fine.

So I checked for a draw with a multimeter. Last week I had something like a 00.12 amp draw (I have no stereo in the dash so the clock memory isn't even there). I pulled the fuse under the hood for power locks and it dropped to 00.02. I figured that was ok and I tried leaving the battery hooked up. Next morning... dead again. So i've just been unhooking it again all week. Today I had time to check again.

Today i'm getting a 00.11 amp draw, when I put the power lock fuse back in it stays at 00.11. I pulled the lock fuse again and started pulling fuses. I have pulled every fuse, relay, flasher and diode under the hood and under the dash and nothing budges it from 00.11. Any ideas on where else the draw could be coming from?

Thanks
Joe

 

[trashtruck]

not saying this is the problem but have you tested the battery? i've had new batteries fail before.

 

[lvin4jc]

Oh the battery is a 2013 piece of junk. Looks like it came from Bob's battery company out of the back of a truck or something. But can it draw from itself?

I unplugged some more things, alternator, lots of underhood stuff etc. Didn't come up with anything. So I took off the smaller power wire going from the battery to the starter solenoid and (maybe this is obvious) the draw fell to 0. So there are three wires on that post of the starter solenoid. The one from the battery, a red one and a double white wire that has one connector on it.

When you touch the wire from the battery to the red wire you get about 00.05 draw. When you touch it to the double white wire the full 00.11 is back. When you touch it to just the starter solenoid nothing draws. When you touch it to the other post of the starter solenoid, it would be connecting to a wire that goes into the bottom of the fuse panel under the hood, it shows about 00.05 draw.

Put it all back together and it's still steady at 00.11.

I'm going to Google what the red wire and double white wires go too. They go down into oblivion and I can't see where they end up.

 

[Rhett]

You say the battery is a piece of junk. I think you just have a batt that is worn out. Their standing voltage will drop overnight from temperature drop alone, and an old one that has bad cells could drop low enough to not start the next morning.

You could try putting a desulfator on it, and it might come back. If you don't have a desulfator, I would junk the battery, install a new one with a warranty, and go from there. At least then you'll know you have a seemingly good battery, and if IT gets drawn down, only then would I start troubleshooting circuits. It's just such a pain to troubleshoot circuits one at a time, that I would rather start with a known good battery first, before going to any more trouble.

 

[lvin4jc]

Yeah I guess I was trying to go about it the opposite way of that. I believe that the problem is in the truck because like I said, when you disconnect it the battery can start the truck fine even a week later. I really don't want to start jacking up my new battery by completely draining it every night.

But I have a new one on the shelf here at the shop so I guess i'll throw it in and see what happens. I certainly can't find a draw anywhere else on the truck. And I can't explain why the door lock fuse pulled a draw last week and isn't today. Still don't understand that part either.

 

[larrydd999]

Take the battery to a shop or parts house that can test it, that way you'll at least know if it's part or all of the problem. Just curious, did you disable the under-hood light before you took the amp readings? the 0.11A sounds like the current draw from a miniature light. IMHO, a 110mA draw overnight should not be enough to keep you from being able to start, as long as the battery is in reasonable shape. After all, the starter takes 200-300 Amps to turn over the engine, and you still need enough voltage to keep the ECU alive.

 

[iLoveMyExploder]

i know this probably wont be helpful... but we had a similar problem with out PT cruiser. i swore up and down the battery was good, but it turned out that it wasnt. another factor that may count in to why that practically new battery died in the first place- the ignition cylinder was broken. i put a new battery in it and replaced the ignition cylinder, and no issues since. ...like i said, that probably wont be helpful since it wasnt even a ford. do like what rhett said and get a brand new battery with a warranty and try that out. see if it dies overnight. if it dont, it was the battery all along. if it does die- you can exchange it for a new one

 

[lvin4jc]

Well it was in fact the battery. At least so far. I put that new one in and even after sitting for multiple days it starts right up now. Thanks everyone, I'll report back if I have more issues.

 

[ChildIdenticant]

if it turns out to not have been the battery, check the glove box. I had similar problem, an it turned out that my glove box door had warped over the years in the heat just enough for the light to remain on.

 

[lvin4jc]

I'll check it. Turns out it does drain after the new battery, just takes a couple of days now instead of overnight. I left it for four and it was totally dead again.

 

[natenkiki2004]

Back to using a multi-meter in-line between the negative battery cable and negative battery post. Pull fuses and relays until it drops to nothing. One thing to note, the alternator can fail in a way that causes it to draw current all the time. If you absolutely cannot find anything else, disconnect it and see what happens.

 

[lvin4jc]

Back to using a multi-meter in-line between the negative battery cable and negative battery post. Pull fuses and relays until it drops to nothing. One thing to note, the alternator can fail in a way that causes it to draw current all the time. If you absolutely cannot find anything else, disconnect it and see what happens.

I did not know that they could fail in that way. I like the theory though, something belt-driven whines when I start it the first time for the day, especially on chillier mornings. It's working but i've been keeping my eye on it because I suspect the whine is the alternator. I haven't been able to catch it with the stethoscope because when I get to the shop the engine is warm and it's done whining.

Alternators aren't crazy expensive, probably worth trying to see if it fixes both issues.

And yes, I have experienced more bad out of the box alternators before than any other car part. This one, however, is plenty old

 

[boominXplorer]

The alt will whine when it is charging over normal amps. Your battery is low and it is just pushing amps at it to recover it.

 

[lvin4jc]

I have experienced more bad out of the box alternators before than any other car part. This one, however, is plenty old

Case and point, I installed a new Alternator this morning and it doesn't charge at all. Voltage gauge reads on the "N" so draining and when I disconnect the battery the truck dies immediately.

Re-installed the old alternator and we're charging well again.

Another bad-out-of-the-box alternator, sweet. I guess i'll try another one