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Discussion Starter #1
Hello All,
So has anyone had any luck in figuring out what is causing the battery drain issue son our trucks?
I've googled the issue until my fingers have bleed and still have not found an answer. In the mean time I will continue to troubleshoot and take readings.
 

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Hello All,
So has anyone had any luck in figuring out what is causing the battery drain issue son our trucks?
I've googled the issue until my fingers have bleed and still have not found an answer. In the mean time I will continue to troubleshoot and take readings.
If you have a battery drain it's easy to find with a DVOM meter. First step is to verify the drain. You should have no more than 300 Miliamp draw with the system powered down. Remove the negative battery cable from the battery and attach a jumper from the negative battery post to the positive lead of the DVOM meter set to Amps. Next attach a jumper from the negative meter lead to the battery cable. <Note that most DVOM meters have a built in 10 Amp Fuse. If you have a big drain you will blow the meter fuse so be careful and if you suspect a large draw an Amp Clamp is a better choice because it won't blow the meter fuse.
Now with the amp meter in place do not turn the key on. Remember the dome light will illuminate and draw amperage if you open the door. Another suspect is the glove box light. Very common battery draw that fools a lot of techs.<G>
Next start removing fuses one at a time until you find the circuit with the parasitic draw. Once you isolate the circuit it's just a matter of checking the accessories on that circuit.
 

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Discussion Starter #3
If you have a battery drain it's easy to find with a DVOM meter. First step is to verify the drain. You should have no more than 300 Miliamp draw with the system powered down. Remove the negative battery cable from the battery and attach a jumper from the negative battery post to the positive lead of the DVOM meter set to Amps. Next attach a jumper from the negative meter lead to the battery cable. <Note that most DVOM meters have a built in 10 Amp Fuse. If you have a big drain you will blow the meter fuse so be careful and if you suspect a large draw an Amp Clamp is a better choice because it won't blow the meter fuse.
Now with the amp meter in place do not turn the key on. Remember the dome light will illuminate and draw amperage if you open the door. Another suspect is the glove box light. Very common battery draw that fools a lot of techs.<G>
Next start removing fuses one at a time until you find the circuit with the parasitic draw. Once you isolate the circuit it's just a matter of checking the accessories on that circuit.
Good info. THx
 

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Did you pull the relays too? If not pull all the relays out. Like Tim said, suspect ANY and ALL aftermarket accessories, brake controllers, stereos, alarms, CBs, anything added that's not a factory accessory including a trailer plug.
 

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One thing I found on my old truck that was draining the battery, was the On-Star even though it wasn't activated. I pulled that fuse and then it was all good, just a thought.
 

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with your truck running check charge voltage at battery with meter set to read AC voltage, if you read any, would indicate bad diode in alternator. This would cause a drain.

Or since you are seeing a drain, disconnect the alternator ......... and see if your draw goes away.


danv
 

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i just got back from getting a drainage issue fixed at a dealership,as it turns out,it was the gauge cluster module that was causing the drain,it was a spendy fix,but at least i wont have buy batterys for for a hundred a clip anymore
 

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I was having a battery drain issue on my 99 Tacoma for a while, it only gets used once a month if even that often, but every time I went out to use it the battery was dead, it was more annoying then a problem.
One day I decided to fix the problem but after checking every wire out of the fuse box I still couldnt find the source. While I was under the hood my grandaughter kept asking me about something under the drivers seat and was basically being a pain so when I stopped work to chase her away she casually flipped the button to release the CD cartridge on my remote CD player under the front seat, grabbed the cartridge as it came out and said fine I'm taking this with me.
Which was just about the time i realized the only thing not running through the fuse box was the CD player.
After digging between the seats and center consol I found the remote and as I thought it was in the on position, if the radios on the CD player still works and for some reason unknown to me now 12 years ago I wired it through a battery hot instead of the fuse box.
Turn the remote off and no more dead batteries, amazing how that works.
 

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Ok, I have a question. I have a 2004 Silverado 2500HD and I've had the same type of slow battery drain. I just hooked up my meter and with nothing else on, I have a .54 amp drain going on. I'm going to start pulling fuses and see what I can find. On top of that, when I open the door to trigger the interior light, my pull jump to 2.6 amps! Everything I've seen says a normal pull for interior lights in around .98 Have I got some crazy interior lights or something?
 

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when I open the door to trigger the interior light, my pull jump to 2.6 amps! Everything I've seen says a normal pull for interior lights in around .98 Have I got some crazy interior lights or something?
Going to depend upon how many lights come on when you open the door. Other things "wake up" as well.
One 10 watt lamp at battery voltage is going to draw 0.8 amps.

Pull the fuse for the interior lights and see if there is still a draw when the door is opened.
 

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Ok, I have a question. I have a 2004 Silverado 2500HD and I've had the same type of slow battery drain. I just hooked up my meter and with nothing else on, I have a .54 amp drain going on. I'm going to start pulling fuses and see what I can find. On top of that, when I open the door to trigger the interior light, my pull jump to 2.6 amps! Everything I've seen says a normal pull for interior lights in around .98 Have I got some crazy interior lights or something?
your .5 AMP draw is too high. should be below .25AMP or lower after about 15min.

with a 12volt system each light bulb will draw a good amount of amps. a 12 WATT bulb will draw 1 AMP. when you open the door the interior lamps will draw a few amps.
 

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went a chevy dealer...parts man claimed he had never heard of a gauge cluster module...where is it located....oh, by the way,they wanted to do a leak test for a $100.00
 

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the gauge cluster has an electronic module on it. the dealership would change the dash cluster. now there is no diagrams available with this . GM top secret !
 

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O.K.

Here is my .2 Cents worth.

And this thread is all but dead, but I have learned much from these Forums and this “Battery drain search”.

First off, I am an Electrician with over 32 years of experience. “Yes, useless fact”.

And Auto Electric is another animal, but that said. The more you work at it the better you get right!

1) Using a D.C. Amprobe on the positive Cable I pulled the Fuses one at a time, at first I noticed no change, but with a little amount of time there will be change.

2) This is where the cooler of beer and a friend come into play.

3) Dust and any Liquid is not good, Tracking can and will occur. Clean and dry is best.

4) Next, while pulling each fuse to search for the drain I used a New “Stainless Steel Tooth Brush” to clean each of the Fuse Tabs.

5) I don’t mean to say REEF on them until the silver is removed; this in itself yielded great results. Oh starting at about 2.2 amps draw and down to .5 Amps and now down to .3 Amps

6) During the search please don’t overlook the obvious like I did, the beer was instrumental in this equation. Doors, Glove Box and The last “Hood Light” that was not even lit. “Not working”

7) So, it’s o.k. for the doors and glove box and the hood to be open as long as you are accounting for each of them.

8) Clean and dry is the take away from all of this. And the finally was the “hood light fixture” has a mechanical Iron Pivot switch. Unplug the fixture to check for drain even if the light is not on.

9) Hi resistance is Not good ever, any hi resistance will cause or simulate Load.

10) The under hood lamp fixture was a mess; I might still have to replace the fixture. Years of bouncing “mechanical Iron Pivot switch” and probably will not hurt to go LED on all of the lamps anyway.

11) I have a DC Amprobe. VOM in line of the ground works as well. Plenty of good information here.

12) Thanks to all that provide support to U-Tube and The Forums, We all benefit from this.
 

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Opdate: I eventually tracked my problem down to a "headlight / dome light switch". problem solved.
It was intermittent and I chased it for the past 4 years.
the hood light is disconnected on all my vehicles from day one. on my sedan the trunk as well. many have had these type switches fail this way. the under hood/trunk lights should have mechanical switches when you need the light switch it on.
 

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99 GMC early body style 5.7L K3500
Hi guys,
This is my first post, I've seen some great question and even better answers I have an ex military 4WD Military Police truck. I added power mirrors, locks, and windows and a cross body harness 10 years ago.
Now it has a parasitic drain. The book says any thing over a 50 milli amp draw is a problem, mine is a 90 milli amp draw., I put a scissor type disconnect in the negative battery cable (got tired of replacing dead batteries) I pulled the fuse for the EVO Passlock Module (electronic variable oriface ) most of the drain went away. However EVO module has its tentacles into just about everything, ((strng) ie. security ie. theft deterrent system including the key lock sensor, Passlock sensor signal, two tamper sensors, tamper resistor, security lamp and non security/theft things like a 5v reference, 12v reference, variable power steering, transfer case controls, instrument cluster gauges, Serial Data Class 2, i.e Data Link Connector i.e. OBD 11 connector. steering wheel sensor, shock sensor, ignition, and a ground etc.etc.etc.)
The EVO module is expensive! How do i test the rest of these things listed above or rule out the EVO module?
Because if the problem is not the EVO module I just wasted big bucks on a used
electric module that i can't return!

Thanks, I hope that one of you has had to fix this problem,.... on someone elses vehicle......for lots of money!
 

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The biggest problem with todays vehicles, is the LAN. Not actually the LAN, just the fact that there is a LAN. When it works, it is an awesome addition; when it doesn't, it causes a lot of grief. An example is RAP (retained accessory power) a series software commands that leaves some "switched power" accessories turned on after the key is removed (this is the system that leaves the radio on for 10 mins after the key is removed).

Here's the problem, back in the day, the ignition key controlled the voltage to all of these accessories, remove the key, the voltage is removed the accessory is turned off.

Today, nothing is turned off with the key, well maybe the engine; today, the accessories are always "hot". Commands are sent on the LAN to put these accessories "to sleep". When they sleep, very low current draw. The problem is, they don't always go to sleep. Then there is a high current draw.

If they all stay on, suspect the BCM, if it is only one that stays on and the others go into sleep mode, of course, suspect the module that doesn't sleep.
Like all other circuits, it's the intermittent one that causes the bare spots on the top of your head.

Of course, we also have all of the usual circuits that cause battery drain, like lights, etc..
 
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