GM Truck Club
Founded in 2004 ~ We're the #1 Chevy Truck & SUV Forum.
Silverado & Sierra | Tahoe & Yukon | Suburban & Yukon XL | SUV & CROSSOVER
Results 1 to 3 of 3
  1. #1

    Default batteries go dead, 07.5 2500HD, deisel

    I have had this issue off and on for almost a year. I park the truck, 07.5 deisel and then a day or so later the batteries are near/ or dead. Two new batteries last fall and it did the same in late Oct while at the dealers so they cleaned and tightened pass side battery cable. We went on a trip and put on 11,000 Kilometers with no trouble. Moved the truck Sat and then Mon batteries dead again. I charged them and started the truck. Battery gauge showed just over 9V and did not start to climb for a good min to 2. When I had it in in the fall I asked about the gauge readings and was told it was normal, I have never seen a volt gauge low just after starting. I wonder if the alt is going and causing a discharge through it. I am now 4000Kl out of warantee. My buddy sugested that I remove both battery +s and connect a light between the main + post and the main cable to the starter and see if there is a drain from something, and if so start removing fuses. Before I go through this any ideas? Also does anyone have a reference as to which fused circuits should be live without the key on? Thanks and good day.
    07 2500HD Duramax , 4DR and 26 Prowler 5th wheel Travel trailer, 57 Chev wagon with 14' Bonair travel trailer, and 71 Nova. Canadian Regional Coordinator

  2. #2


    The only thing that I have seen that causes that problem is the alternator is junk. I would see what it is putting out while running with no load on it, and then with a load (a/c, lights, radio, etc) if the meter drops significantly then the alternator is junk.

    2003 single cab stepside Chev 1500, 6" rough coutnry lift, 4' firestick cb whips, cobra ltd cb radio.
    Next mods: flowmaster 10series muffler and exhaust (in process)
    1.5" zone body lift
    315/70r16 cooper stt once the 305s wear out

    Sold-1996 Audi A4 lowered on H&R ultra low coils running 19" mercedes wheels, limo tint, borla exhaust
    New ride 96 VW jetta lowered 2.0l 5 spd

  3. #3


    It could be the alternator... I would have it tested. A friend of mine had a nissan maxima that would sometimes do as you described. It would be fine for a month then the battery would be dead every morning. He replaced the alternator, battery, and cables. He even had the electrical system gone through. Never did figure it out..he ended up selling it.

    Chances are he had something remaining on that would drain the battery...your friend has a good idea with the light. I dread electrical issues in the newer cars and trucks...make me cringe.

    GMTruckClub members receive discounts off our normal rates! PM me for quotes! Check out our Films gallery - updated with over 200 Hydro Dip films!

    If it can be painted - it can be Hydro Dipped!

    Get the Gorilla!

Similar Threads

  1. my 1979 chevrolet deisel c10
    By 1979silverado in forum Member Introductions
    Replies: 2
    Last: 03-02-2012, 05:18 PM
  2. 2003 silverado 2500HD durimax deisel
    By rkranch in forum Chevy Silverado Forum (GMC Sierra)
    Replies: 0
    Last: 02-20-2012, 10:30 AM
  3. Dual Batteries (Aux) GMT900 2500HD Crew Cab 6.0L
    By Combat_Vet in forum GM Electrical Tech
    Replies: 11
    Last: 12-21-2011, 02:37 PM
  4. Replies: 0
    Last: 04-23-2010, 06:20 PM
  5. GMC Sierra Qs and which: gasoline or deisel?
    By skk951 in forum Chevy Silverado Forum (GMC Sierra)
    Replies: 1
    Last: 03-27-2010, 01:46 PM

Tags for this Thread

Posting Permissions

  • You may not post new threads
  • You may not post replies
  • You may not post attachments
  • You may not edit your posts