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  1. #1

    Default gas gauge erratic at best

    The gas gauge on my 99 goes down to half a tank if it goes down that far, then starts going back up again. I'm just filling up when I get to 500 miles on the trip odometer. Is there a fix for this without dropping the tank?

    Any suggestions?



  2. #2


    Either fuel pump itself or grounding issue at tank. You'll probably have to drop it. Sorry. Good luck


    2007 Ford E250(Work van) (Ya, Ya, shut up!)
    1996 GMC Sierra SLE 1500 5.7L/4L60E

  3. #3


    Thanks for the quick reply. It runs fine. Just an annoyance really, but I figured if I could fix it without too much effort, then why not?

  4. #4


    Its seems to be a popular prob with 99 trucks in general for GM. My 99 Savanna flickers but I've seen the symtoms like yours on one of our other Savannas and tank had to come down to get at ground strap. People have posted here with same probs before(From Suburban to C/K)...I know that sucks.

  5. #5


    Mine started acting erratic just before the fuel pump quit. It's not to hard of a job on the 99's as long as the tank isn't full.

    99 K 1500 Suburban
    78 Silverado Big 10 w/factory 454
    00 S-10 Blazer
    1976 Trans Am
    1980 Honda CB900 Custom

  6. #6


    mine used to do that (99 old body style sierra) now it just sits on full all day long.
    1999 GMC Sierra 2500 350 vortec
    1967 Jeep M725 ambulance 230 tornado
    1990 Cherokee Limited- 3 inch lift on 33's
    ...and every one of em has issues

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  7. #7
    Jr. Apprentice
    Join Date
    Sep 2007
    Victorville, CA


    My 00 Safari had that problem. It was the Fuel Pump / Sending unit. It was located in the gas tank.
    2008 Suburban Blue Granite Metallic
    LT2, DVD (Headrests), Sunroof

  8. #8
    Legend unplugged's Avatar
    Join Date
    Sep 2006
    High Deserts of SoCal


    The bounce in mine is more pronounced near 1/4 tank. I try not to let it get that low so I don't run dry! An erratic gauge isn't so bad when you have a 42 gallon tank.
    There is no way to happiness....happiness is the way.:yipi:  _vXMYypuKMJFw671uF2ZPhjez_j-atRmcjM2zQKpQi1JSsB75/burb1.JPG
    High Desert SoCal
    93 K1500 burb (personal) 350 AT 3" Lift 250K+
    02 Honda Civic LX
    Looking for a 1990's Miata for an engine swap

  9. #9


    My 96 did it when I first bought it, found out it had been doing it since it was new...he was just too damn lazy to check it out. I also had an erratic speedometer...actually reminded me of the old days when you would have to lube the speedo would jump around sometimes, or just plain not work. Found out from a GM tech buddy of mine that it wasn't too common of a problem, but it did happen on some of the trucks. Turns out the gauge went bad, no ground or fuel pump problem. I replaced my cluster and it has worked fine ever since.

    Not saying that would solve your problem, but that's exactly what mine was doing, and it solved it.
    Here's my truck!

  10. #10


    Thanks for all of the replies! Is there any way to test the ground or the sender? How do I know if it's at the tank or if it's just my gauge?

    "Help, I'm surrounded by Amish!"
    1999 GMC Suburban 5.7 4x4
    2001 Subaru Outback 3.0 LL Bean
    1980 VW Rabbit Convertible (before they went Cabriolet)

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