In this video I look at a 2014 Chevrolet that has a customer complaint of the battery dying overnight. Indeed he is correct, it has a big draw sucking the battery dead in several hours. Let's have a look to find the issue. -Enjoy!
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Hey there viewers and welcome back to the self made knowledge. You know. That's our 2014 chevrolet, it's a gmc, 1500 uh kind of the same thing. It's got.

The big five three customer complaint is that the battery is always dead. It appears to have a newer battery in it when i went to pull it in, and indeed it was smoked. There was nothing a zippy zap, not even a dinger uh threw a jumper on it, brought it in threw it on the charger for an hour. So left it on nuclear got a bit of a charge and it starts under its own power.

Went through, you know, shut the key off opened the door latched all the latches uh we've got our vantage multimeter hooked in series, so we're running current through our meter. So we can let it sit here for 20 minutes half hour whatever to see where it ends up right. Now it's holding pretty steady about 800 milliamps, but i do want to give it some time it's only been about. You know, 10 minutes.

However long it took me to do that stuff so in about a half an hour, 40 minutes hour or whatever we'll check and see, is that current draw at that current time? If it is that's way too much and then we're gon na use the process that we've always used to track it down and see where is it going? I guess it's been about nine minutes because that uh clock and it resets, because i always yank the battery out of it uh so we'll give it some time - and you can see i'm just over here in uh series with the battery in line with the battery. I did unhook the uh little blinky light rust, evader gizmo, that all the dealers sell just so and they only draw like one or two milliamps, because they're fake so we'll leave that on hook that way, we don't get the bleep and light um. The the blinky light over on the little magic box you can see that we have something that spikes it up to almost a full amp periodically. I don't know if that's normal or not, but we'll give her some time see folks in uh, you know half hour 40 minutes, because i have the patience of the squirrel uh when i'm trying to hurry up and wait uh.

It's been 17 minutes when i busted out the dvom. Now you guys have seen in previous videos, if not i'll, put a link on how i check for a parasitic draw and essentially what we do is we measure current or we measure, i'm sorry voltage drop across the fuse, because, if there's current flow through the fuse, There's going to be voltage drop across the fuse. Otherwise, if there wasn't the fuse, wouldn't work um. So then you know we go down through and, like i said, you'll watch that video you'll see how i did it.

So, as i'm waiting for this thing to to go down, i'm just kind of poking along and seeing who's hot who's, not - and i got over here to this 20 amp fuse here and if i put my test, leads across it. This is as far as i've made, i haven't gone across all of them yet, but let me uh get it under these fuses they're getting smaller and smaller kind of pisser, but i have about 52 to 53 millivolts of voltage drop across this fuse. Now, if there was no current flow, it should be like this fuse here. I don't know if you guys can see the meter or not, but essentially let me make sure that's correct now.
This fuse could just be open also, but that's 0.00 millivolts, and when i come here back onto this one, we are at 52 to 53 millivolts but, like i say that could be um from an open fuse too. So we're going to yank that out, because i'll show you that, if that fuse is open, we could be just getting tricked. Let me get a pair of so what we're going pliers do is we're going to yank that fuse the voltage over there did not or the current draw did not change over there and sure as thunder that sucker is open. So that's that's junk um! Let's see where were we over here? It's a cluster of four number fifteen one.

Two three fifteen trailer park lamp so anyhow, so that's something to do with his trailer lights. Uh like crappy wiring, on the trailer anyhow. I just wanted to show you that i don't know if you can see my screen but uh. If you see something like that, don't get too awful excited because that's what it could be could be a simple open or could have found the problem.

Unfortunately, we're still waiting, i'm still impatient and i'm still going to keep checking 32 minutes has passed folks, even though it's been mere seconds too now i have gone through every single fuse here. The left side instrument panel fuse box right side well, all while waiting patiently uh and nothing every single fuse that is accessible, so these little low profile fuses or whatever they call now and the mini fuses and the triple fuses uh. None of them all is 0.00. So it's kind of interesting because typically one of these circuits will feed you know other circuits inside and usually we'll start to narrow it down now uh.

The next thing that has to be done. That is not as easy are these jk fuses, which, on these chevrolets, you can't just pop the covers off them and and go across them. So they have the plastic. You know lid on them, so the only thing you can do at that point is an old dance.

I call the hokey pokey and you need to use pair of pliers. You don't need to turn yourself about. However, i hate doing the hokey pokey simply because when you you know, grab a hold of one of these little guys. You got to be careful because you can break them if you squeeze them and then, when you pull it out and stick it back in, sometimes it resets, you know whatever module it may have been feeding, which is a pain in the who, and you know i'll, Save you all the heartache and pain i went through and i'm doing hokey pokey out here and i'm getting all the way down, and it's always the last fuse.

You pull. However, in this case indeed, not only was it the last fuse i pulled, it was actually the last use in the box to be pulled. So this fuse right here and uh. Let me get my meter.

Let's see we're going to look at this again, i haven't gone any further than what i just told you now. Let me come around here, we'll we'll get a little uh uncomfortably close. Ah, let's see, can you see that if i get it just right, i should make it have a glare and nobody can see anything. 7.
92.. Let's back out of this, let's just get uh some digital action up here it may be easier for you to see and i do care, despite what you may think. So, let's see, can you see that 792 milliamps? Now we go come over here? The absolute last fuse pretty sure my eyes did not deceive me. There you go and strikingly enough when i reinstalled it.

Oh wait a minute. Oh, you hear that fella you hear that indy there's something going clicky clanky when i do that, but i was going to say oddly enough, when i reinstall it, it just goes back to the 800 milliamps there's something down yonder that is uh clicking. However, that's perfect. So that's good and let's see where we're at here make sure we got this right side up number six.

So it's this fuse in the fuse box. Numero 6-0 units trace four five. Six four-wheel drive track, 4wd, trec, 30 amp and i do hear something clicking under there. That's weird, let me uh, i think this thing's kind of a stripped down jobby.

Let me look inside see if it's got the shifter in the floor. Nope, it's got the knob on the dash he's got a four button: selectable knob, two wheel, four, look: four wheel: four low and auto we're gon na leave that out we're gon na get us a diagram because we need to know who does this little guy run? Is it the shift motor? Is it the transfer case lock uh, because i believe these have a locked solenoid on the transfer case uh or what in the thunder it feeds and then we'll have to? I don't keep doing the hokey pokey. So i got some diagrams folks. I think we are safe, we'll turn this off for now.

Just so our battery doesn't go bad and that's turned out from center stuck to the side. So we tracked that down uh relatively quickly. There then we're impatient. We didn't just keep waiting uh.

Let me get a pointing apparatus we'll utilize this here now this is a power distribution diagram and i know it's not ideal trying to show this but uh. Let's see here. Let me find this one again. So it's right here and just let me move my camera here a little bit.

So, let's see right here so this uh 4wd trek fuse 30 amp. That's when we're at it comes down. It feeds the transfer case, control module and also feeds the transfer case motor. So now we know the two things uh that it that it does and being that it feeds that motor and we hear it clicking under there.

I got us a diagram for uh for that something a little more detailed uh, so we'll have a little peek here that so, let's see here, i tried to simplify it. I tried to uh, highlight it before i printed it, so there's our fuse again. So we're going to file both of these out so now this leg comes out, goes over to another diagram. Comes out of.
There comes up into this instrument panel junction back out of that junction down here across down back to 19 over here, and then we can see it is the battery plus for the transfer case, shift control, module, lower left-sided dash so uh, and it is hot at All times so that feeds the transfer case, module now, we'll look at the other leg of it that comes out goes over goes down round it down comes over here down and boom transfer case motor on transfer case. This is what we're hearing down here now. I believe uh, you know our symbol down here. That is our actual transfer case motor and then there is a position sensor, rotational sensor here of some sort.

I believe uh on these, i haven't worked on a ton of these four wheel drives yet, but enough to know, i think that's the case if we followed that back uh, but that's neither here nor there because we're looking at this here and that's a solenoid, and I believe it's the transfer case lock solenoid. Now these transfer cases, i believe, have to lock and unlock prior to engaging the motor. You can't just apply power to this motor and make the transfer case motor shift um. I know that because i had a guy that burnt his almost to the ground, uh trying to run jumper wires to it, and that's how i know that, because i remember like oh yeah, wow yeah, okay, it's got a lock.

You got to disengage the lock to turn the motor on, so i think that's what we're hearing uh. So if that's the case, of course, i've got these wires now so they're not very bright, so we can't see them, but we're going to see in order for a solenoid to work. It needs a power supply, but then it's going to need the ground supply. So, let's see where that comes from, yellow brown goes up and around down over goes to number nine.

The niner goes over here transfer case, lock, solenoid control. So what does that leave us for options? And we know, because it has a full time power that that has to be a ground side, switch to turn that lock on and off. So the options are something in this control module over here is saying: hey unlock that little fella little fella or b. This thing's short of the ground, so what i would do if it were me - and in this case it is we're going to go down to this connector - this big honkey right here, because this thing could be either receiving the command to lock or unlock.

I guess it is, i don't know which way it goes. I think it unlocks um or the transfer case. Motor here is just junk and we unplug it if we unplug this connector jumper just power to this, and that thing still goes, then we know the transfer case. Motor is junk.

Now, if we go down here - and we check this - and this is indeed receiving a ground signal to say - hey unlock me little guy - then we know all right. Well, we got to chase this out. Is this wire short of the ground? Is the transfer case, control module, gone wonky and you know trying to do thing on it on its own, with the key off? That's what we need to find out. Let's go down on this little girl and see what we got down there: we're going old school here, folks wow.
How do you guys do this? So there is our daewoo shift motor. It says: smt, daewoo, okay, here's our wires! That's for poop and laughter, let's unplug! It come on baby, i'm gon na set you down folks, so it is unplugged, and i don't see now, if we're gon na end up chasing this, you know if it's a short to ground, then we'll obviously throw it up in the air but uh. It feels like everything is kind of attached back through here, doo doo. I don't see any green crusties uh.

Theoretically, we can go up there and put our fuse back in it and we should no longer have a draw. Let's just go double check that i'm sure this is what we heard: uh clicking and clunking under i'll move here back up, so we can see, but i think more obviously we'll be able to see if it clicks yeah. I don't hear any clicking we'll insert that fully and then we should still be good here, because i haven't opened the doors or done any of that. Oh okay, perfect! So we've isolated it too.

How much you get buddy! We've isolated it to that uh to that motor. Okay. Let's keep going now yellow with a brown that should not have a ground on it. We've determined - where was it here transfer case, lock, solenoid control that should not have a ground on it.

So, let's grab a powered test light and see if that is the case, yellow is brown because red with grey is supposed to be our power and then yellow brown uh, which is right, got yellow purple, yellow black assume, yellow brown. Hmm did i bring my diagram down, gosh dang it. I didn't. I think it's the one right next to it.

I think it was c and d. Ah, you ding dong. Well, anyhow, we'll have to double check. So technically our fuse is back in so we should have power here we do and then this should not be a ground and it's not it's not it's not dinging away at us, anyways.

Okay, what we'll do it's? Like a ding-dong? I forgot my diagram. We're going to have to double check that to make sure so that's good. We should not have a ground on yellow brown, no ground on the yellow brown. Unless the module was trying to unlock it, it looked like it should click yep.

I do believe that it is shorted internally now another way that we could do this if we could see up in here, if i get a mirror, we can hook to just the lock wire, so the second one in from the left side. Here we could do that with our power probe apply power to it. If this thing locks, then it is then, is junk, because theoretically, it should not be able to activate that solenoid without the other side of it. Okay, let's see i'm just going to try to feel the pins here.
You hear that folks that transfer case shift motor it's absolute garbage, so i'm hoping that made sense to you folks, let's just look at it as um. How do i look at it? You know we could look at it as a light bulb. Perhaps or anything you know a load. You know it's just a load, so we have battery plus going into a load, in this case a solenoid and then to turn that solenoid on.

We need battery negative to activate this, whether it's a a motor or a bulb or a solenoid or whatever you know, whatever it is whatever type of load. That is, we need power and ground turn it on in this case. In this case, we know we have a full-time power because that's our fuse and then the negative side is done. You know by in this case, by control module the transfer case, control module.

That's what turns that on and off you know a transistor. So once we identified that this fuse is the one drawing current we could hear this solenoid clicking. So we know you know our power is going down there. It's going through and stuff.

We need to determine. Is this thing shorted out somewheres inside the transfer case, uh, locked, solenoid or inside that shift motor, or is this wire actually doing what it's supposed to be doing? Is it you know providing a ground when it's technically not supposed to so we went down with our power probe, we unplugged it and we could see you know once we unplugged it. We had. You know battery plus here, which was obvious, and then we've seen here, that we had no ground, which was good, because that tells us that there is no ground supply.

Therefore, this has to be shorted internally to prove that we took our power probe and we hooked on to just this side of it. You know isolating you, know the ground side and plus side, and we applied our own power to it completely open circuited. On this end, and it clicked, we heard it thereby making this the culprit. It is 100 shorted out inside of itself providing itself with its own ground.

So hopefully that makes sense to you. If not, i failed miserably, in which case you'd want to go. Watch this guy because he's awesome, so that's that folks, a bad transfer case shift motor causing your battery to die overnight. I don't make it up folks.

We just follow the facts uh so before you go and start unplugging your radio and sending your cluster in and changing your alternator and 13 different batteries. You know just use this process and we have to follow the facts. So the easiest thing most non-invasive thing to do is how we did it, which we've shown in other videos voltage drop across accessible fuses. After that one leg again one leg out: you do the hokey pokey you pluck the fuses, which sometimes is not great.

We also learned that sometimes open circuited fuses can give you a false positive, so just be mindful what you're looking at and follow the facts get the diagrams. Where do you get the diagrams? I've done a video on that. Also you can go on. You can get the diagrams, you don't need big fancy, scan tools and expensive stuff to do this dvom.
I like to use this one simply because it's easier for both of us to see and as i age that's a thing uh and that's that the thing i want you to do before i age anymore is head to that comment. Sections the comments, the questions, the concerns, the insti, the facebook and just my reviewers. I can do it, you can do it thanks for watching.

By EricO

9 thoughts on “Chevy Truck: Battery Dies Overnight”
  1. Avataaar/Circle Created with python_avatars Dan says:

    Great video !!! I seem to have forgotten correct procedure on how to hook the meter up correctly in series? would you mind explaining it please and thank you

  2. Avataaar/Circle Created with python_avatars MacDonalds Motorworks says:

    the one thing you have to be mindful of when doing a voltage drop across a fuse is to make sure you also watch the draw on (ideally) a digital scoping DVOM. If you only measure voltage when the pulse isn't occurring you can miss the voltage drop. I had a wiper motor that did this a while back and it wasn't until I connect up my pico and did the voltage drop that I saw the fuse that was the culprit. Go slow, be thoughtful I guess is my motto on these ones!

  3. Avataaar/Circle Created with python_avatars Ralph Adams says:

    I thought you n ur channel were goners ,but I did find out I was UNSUBSCRIBED,I did not do that, sorry but da evil you tube gods did IT!

  4. Avataaar/Circle Created with python_avatars tin pin says:

    I wanted to thank you for your parasitic draw videos because I was able to find a draw on a customers vehicle at my parts store parking lot tonight in fairly short order with just my clamp meter.
    My long-winded story:
    I had a customer call my store looking for a Noco jump box because the battery in her 2017 Pacifica was completely draining overnight. I told her what I had in stock and remarked that I'd like to try out a toy I bought for my store (an ac/dc current clamp and meter) specifically for detecting suspected draws like hers. She agreed.
    Turns out she is physically handicapped and was not able to get an appointment to get her vehicle in for service any time soon, so I asked if she had 20 or so minutes to see if I could figure out what circuit was at fault rather than just confirm a draw. She said sure, so I investigated. I tripped her door latch and checked her negative cable – 1.1 amp draw after 15 minutes of sitting. I told her that I wasn't going to mess with the pain in the ass jcase fuses but I could look at the ATRs under the hood but it was a longshot that I'd find the issue. Lo and behold I found a 4.4mv drop on the infotainment cluster fuse! I yanked that puppy out and rechecked the draw – 0.009 amps!
    When I asked her is she had had anything weird going on with the system, she had a very entertaining story to tell: one of the times her battery was drained she was waiting for AAA to show up while sitting in her car and while the vehicle was completely off… NOT accessory or run with no screens or lights on at all… She noticed her phone was connected to something via bluetooth and playing music, and if she was completely silent she could very very faintly hear singing through the car speakers!
    "The car was COMPLETELY off with everything black??!" I asked. "That's right! NOTHING was on, not even a dome light when the door was open!"
    "Well, there's your problem lady!"

    Anyway, thanks again for your videos we both really appreciate it!

  5. Avataaar/Circle Created with python_avatars Wolfman Rebel says:

    I typically love stuff like this, I learned long ago not your average dude can hunt electrical grimlins, I worked at a shop over a decade ago that ALL other shops around would refer the customer to us for impossible to figure out issues ,many/most of which was electrical I have seen alot of stuff worthy of story telling BUT,I own one right now and honestly I haven't put in much time or effort to figure I just hooked the battery when I need it and unhook when I'm done it's a 53 ford jubilee tractor, gas, carburetor,12volt negative ground (some back in those days were pos to frame for those that are unaware) it's been converted to 10si (gm1 wire) alternator , points ignition ,toggle switch where the keyswitch should be ,factory NSS starter button OE type and location , here's whats somewhat unusual 😂 if you leave the battery hooked up it will be dead in a few days,bit short of a week UNLESS you turn the engine to where the points are open,what's strange is the points are not prematurely burning,not sticking and doing fine , HOWEVER, I put a points eliminator kit on it and after plowing 3 fields,mowing 3 times the pickup module crapped out (not unusual from reading comments on the product though for that model) put the points back on and works great for nearly 2 years,like I said I haven't dug into this issue cuz honestly I don't think about it but when I'm using the tractor I just find it strange clearly the points are making a circuit BUT it's not enough to prematurely damage the points.

  6. Avataaar/Circle Created with python_avatars Shelley Samsel says:

    Just found your channel a few nites ago while stranded with my 2001 Pontiac Grandprix GTP 3800 series 2 super charger!
    I want to compliment you on your video's and your knowledge. I am a wanna be mechanic and have watched my share of videos in the past 20 yrs regarding my car. Bottom line just wanted to say thank you for sharing your knowledge and awesome videos!!

  7. Avataaar/Circle Created with python_avatars jorge fernandez says:

    I find these battery draw videos really interesting and informative to watch. Your method is spot on in finding the trouble. You have shown us time and again how to get it done in the most efficient manner. Keep them coming. Hey, at least you didn't get gas in your eye this time.😁

  8. Avataaar/Circle Created with python_avatars Nelson Narciso says:

    Question… if the fuse is popped how is there a voltage drop if there's no current flowing through the fuse??? Thanks
    Great videos.

  9. Avataaar/Circle Created with python_avatars Alan Rodriguez says:

    Very good and shows good interpretation of voltage drops in relationship to where and when the voltage drops occur. When an excessive voltage drop should not occur. Nice examples of voltage ⚡ drops.
    Al

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