"Service Charging System" dash message.

Discussion in 'Maintenance' started by Boatcephus, Aug 5, 2015.

  1. Boatcephus

    Boatcephus New Member

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    Looking for some tips to clear up this annoying info center message on my Z71. Have been dealing with it for over 2 years now.

    All the clues I can provide:
    - Dash info center message "Service Charging System" appears after I idle for about 10 seconds or so. Red battery warning light also illuminates on dash along with it.

    - I have replaced the battery (Duralast), then rebuilt the orig alt, then replaced that alt with two successive new 145 amp alternators; no change, much frustration.

    - Dealer diagnostic returns "B1492 Generator F-terminal Circuit Low-Low voltage from alternator", they suggested replacing the alt, which I have now done 3x.

    - My own handheld cheapo diagnostic never finds any DTCs for this particular problem.

    - Headlights flicker after a few minutes of driving, interior AND dash lights do the same. Just kind of pulse. Figure this is linked to the problem. Did they start at the same time? Honestly don't recall, but I think so.

    - 2005 5.3 Silverado Z71 crew cab. 132k miles, rebuilt tranny at 97k. Black!

    - RPO info seems to indicate my truck uses a 145amp alternator. I currently have a DR44G part # alt, which should be a 145 amp.

    - Truck runs fine, just want to banish the annoying message and would love for my lights not to flicker noticeably when needed at night.

    - From what I've read, this evidently happens when some electrical gizmo detects a current variance of +/- %5 on another electrical whatzit, so if I start the truck and
    immediately drive off, I never get the dash message. It only happens when I idle for something like 10 seconds, and then you have the message for the entire trip.

    - FYI, this model does not have the second battery bay, like most Z71s seem to.

    - I have no abnormal electrical drains on my truck. Stock radio, no amps or extra lights. Do have factory heated seats, fog lamps, push button 4x4.

    I am wondering if it would help (or hurt anything) to try going up to a 150 or 160 amp alternator?

    I hope someone out there can tell me exactly what to change out, re-seat, clean, or smack to fix this annoying problem. Thanks for your time!
     
  2. silverboy02

    silverboy02 GMFS Member

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    sounds like a wiring issue. check all the connections and grounds. get parts somewhere other than autozone as well. I've never had luck with autozone crap.
     
  3. benz88

    benz88 GMFS Member

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    Had it happen on my 04. played with the Alt Connector and it fixed it lol
     
  4. ron7000

    ron7000 GMFS Member

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    definitely check the 4-pin plug that plugs into the alternator.
    you may just want to mail order a new one and splice it in, they are notorious for making a poor connection causing various charging problems.
    other thing that comes to mind is the problem is in the instrument cluster giving a false message, wanna say i came across this sorta info when i replaced the stepper motors and bulbs in my instrument cluster a few years ago. you may wanna call/email a few repair shops that advertise "GM cluster repair" for the ~2000 to 2006 GM vehicles that had the cluster recall and see if they know anything about it.

    not sure what connector type you need, it'll be based on your make/model and alternator type, shouldn't cost more than $10
    http://www.repairconnector.com/categories/ALTERNATOR-CHARGING-SYSTEMS/GM-ALTERNATOR-CONNECTORS/

    before you do anything and spend any other money i would replace that 4-pin connector.
     
  5. Boatcephus

    Boatcephus New Member

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    Revisiting this issue, no change after cleaning the grounds I found. I cleaned and tightened the one from the negative terminal to the frame under the front left fender, also found two together under the driver's door on the frame. No change. My alternator appears to have a two-pin connector, not four. But I am game for trying about anything. Might try to change that wire out.
     
  6. John Clark

    John Clark GMFS Member

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    I've had similar dash light flickering when the battery terminals were dirty on my 02 Z71. They looked perfect on visual inspection but when removed found corrosion on the cable underneath.
     

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