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  1. #1

    Default Electrical problem, battery drain. How much is too much?

    My battery has been getting weaker and weaker and there was something that was draining my battery (12.7V upon shutting down to 11.3V within an hour or so and continuing to drop). Nothing new has been installed, I do have an aftermarket alpine radio with the factory beeper thing and amplified antenna. The truck does sit more than it had in the past, being driven more like once a week instead of 2-3 times a week.

    Truck is 2005 Silverado 2wd, manual HVAC controls. I havent had any of the speeds go out on the controls (ref the blower relay problem).

    After confirming that there is a battery drain, I checked the fuses and found the following fuses pulling power while the truck is off.
    TBC Bat(10A) - 54 milliamps
    HVAC/ECAS(10A) - 45 milliamps
    RVC(10A) - 34 milliamps


    I left those three fuses out overnight as well as unplugged the blower relay under the dash and there was minimal drain on the battery.

    Does anyone have any idea what acceptable numbers are for those fuses when the truck is off? I know the TBC fuse has the gauge cluster and radio on it, but not sure how much power that stuff should be pulling.

  2. #2

    Default

    They are not high drains, but maybe enough to pull down the battery.

    A lot of modules will continue to draw current after the key is off, they require a little time to "fall asleep". How long after the truck was turned off, did you take the readings?
    Ray

    '09 Avalanche LTZ - Black
    '05 Envoy XL (sold)

  3. #3

    Default

    Those readings were taken within an hour of shutting it off and again after sitting 12 hours.

  4. #4
    Sr. Engineer
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    Default

    Milli amps will not do this.
    RESIDENT NUT.....MY CLAIM TO FAME .....

  5. #5

    Default

    Quote Originally Posted by aero View Post
    My battery has been getting weaker and weaker and there was something that was draining my battery (12.7V upon shutting down to 11.3V within an hour or so and continuing to drop). Nothing new has been installed, I do have an aftermarket alpine radio with the factory beeper thing and amplified antenna. The truck does sit more than it had in the past, being driven more like once a week instead of 2-3 times a week.

    Truck is 2005 Silverado 2wd, manual HVAC controls. I havent had any of the speeds go out on the controls (ref the blower relay problem).

    After confirming that there is a battery drain, I checked the fuses and found the following fuses pulling power while the truck is off.
    TBC Bat(10A) - 54 milliamps
    HVAC/ECAS(10A) - 45 milliamps
    RVC(10A) - 34 milliamps


    I left those three fuses out overnight as well as unplugged the blower relay under the dash and there was minimal drain on the battery.

    Does anyone have any idea what acceptable numbers are for those fuses when the truck is off? I know the TBC fuse has the gauge cluster and radio on it, but not sure how much power that stuff should be pulling.
    That is only a total of 133 milliamps or 0.133 amps. Not high enough to drain a battery within an hour.
    You can even go up to 200 milliamps and not have any battery issue for a week.

    Say you have a 40 Ah battery, theoretically, for a 1 amp load, it should last for 40 hours. (realistically, maybe 20 hours)
    For a 0.133 amp load, it should last for 300 hours. So it should not drop within 1 hour.
    Have the battery load tested at your nearst auto parts store.
    2011 Chevy Silverado LT 4WD 30k miles
    2001 Suburban 2WD, 5.3, V8 185k miles
    1993 964
    1996 318TI

  6. #6

    Default

    I know that this is not related to your draw with the fuses that you specified, but if it has lighted mirrors on the visors I would take a look at them. I have seen the hinge break and let the lights stay on all the time. Hard to see them if you are not in a dark garage with all the lights off and your interior lights off.

    1995 Silverado 4x4
    6" BDS Suspension Lift-3" Body Lift-Add A Leaf in rear -Trailmaster SSV Shocks-Duel Steering Stabilizer Kit -AirAid Cold air intake-
    4.56 Gears with Detroit Auburn Locker-Pro-Comp Traction Bars with duel shocks-Aluminum Skid Plate Kit-38.5" x 16.5" Mickey Thompson Baja Claws-Constant Dropping fuel gauge

    2005 Yukon XL Jet Power Programmer, Bilstein Shocks, Bilstein rear springs, Helwig Anti-sway bars, EGR Window Visors, EGR Hood Shield, Denali Headlights, Headlight harness upgrade, GE NightHawk Bulbs, White Night Rear lighting system, Russell Braided SS brake lines, PowerStop Brake pads, PowerStop cross drilled and Slotted Rotors, http://www.gmtruckclub.com/forum/sho...5-GMC-Yukon-XL
    2002 Silverado ext cab 2wd (Sold)
    2003 Yukon XL (Totaled)

  7. #7

    Default

    I'll have the battery checked out...was hoping to not have to replace it. Guess I'll also get another lead for my battery tender to make sure it stays healthy.

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