All lights dimming frequently when engine is running. Saturn SL1 1999..HELP.

Discussion in 'Saturn S-series' started by pekerhed, Sep 27, 2004.

  1. pekerhed

    pekerhed Guest

    I have a 1999 Saturn SL1.
    My headlights and dashboard lights dim often while in IDLE.
    Recently the problem has progressed while in movement. It seems that when
    I shift, the dimming will also occur. When I accelerate, they light up
    like normal. I also observed that when the "dimming" occurs, the air
    flow(AC FAN) also weakens no matter if the A/C is on or off.
    What could cuase this?
    When I turn the engine off, and I'm powered by only the battery, all
    lights are consistently lit. But once that car of mine's engine is
    turning, the dimming begins. The idle also seems to fluctuate as well,
    while sitting at stoplights.
    Besides that, the car runs fine. Accelerates fine. Sounds fine. It's
    just the energy fluctuating while driving that is starting to concern me.

    I saw on some other site that someone said they replaced a PCV VALVE
    when their car "surged when starting" and "stalled at idle" . My problem
    isn't identical to theirs, but in the same ballpark. CAN YOU GIVE ME SOME
    ADVICE more specific to my problem?

    pekerhed, Sep 27, 2004
  2. pekerhed

    KentS Guest

    i think i have the same problem too. but it might be the battery. mabye
    some loose connections on the battery terminal. because when your car
    starts to move the connections will become loose. but other than that i
    dont know what to tell you. it seems like i have had some kinds of
    flucuation in my dash lights too. or maybe you can adjust you dash light
    knob and put the setting on high.
    KentS, Sep 27, 2004
  3. pekerhed

    pekerhed Guest

    Yeah...I tried adjusting the the setting all the way to high. It does it
    less, but it still does it. But, I think that just covers up the problem.
    I still have my headlights dimming and my air fan fluctuating....I have to
    nip this one in the bud. Thanks, anywho...appreciate the advice.
    pekerhed, Sep 27, 2004
  4. 3 things

    * Check the battery connections and that they're tight and clean. if
    the battery's more than 2 years old, replace it.

    * Your alternator could be acting up. Can you replicate this problem in
    your driveway without moving? If so - measure the voltage at the
    battery terminals and see if it goes up and down. Use an analog meter

    * Check for loose/broken/corroded ground straps.
    Philip Nasadowski, Sep 28, 2004
  5. pekerhed

    pekerhed Guest

    Yes, I was able to replicate the situation while parked with the engine
    running. It seems that when I take my foot off of the accelerator, the
    engine idles very low, and then back up to where it should be. When the
    idle goes very low, I can feel the car slightly vibrate, like it was
    thinking about stalling, but changed its' mind.

    I'll check my battery. If anything that I just said in this entry helps
    you determine my problem more, PLEASE share that with me. I appreciate all
    of the help so far.
    pekerhed, Sep 29, 2004
  6. Yeah. It's starting to stall and the computer's trying hard to keep it
    from doing that.
    Check the charging system with a voltmeter. I'm almost certain you've
    got a charging related problem , or a corroded connection. It should be
    making decent voltage (13 volts - anyone got a better number here?) at
    idle (1000 rpm or so). I dont' think it should 'pop up' when you rev
    the car.

    See if the voltage goes up at the battery whenyou rev the engine. If
    so, suspect the alternator or the cables leading to it. I'd start by
    cleaning all the connections - taking them apart and making sure they're
    clean, oil free, and assembled good and tight.

    Naturally, disconnect the battery when you do this :)

    And, check the ground connections and ground straps between the motor
    and body. They all come together on a stud on the motor, IIRC. Clean
    it good, make sure it's dry, oilfree, and tight.

    Ditto for the connections at the battery.

    If it's still acting up, then suspect the alternator. When you replace
    the alternator GET A NEW BATTERY. A bad battery can waste the
    alternator, and vice versa.

    Once you've got a stable charging system that's working right, the car
    should idle properly. if it's not, then you need to totally clean the
    throttle body. Actually, if yours looks dirty now, I'd do that before
    replacing anything but the battery (but do check those connections!) I
    like to remove it and remove the TPS and IAC and clean it totally, then
    wipe the IAC off so it's clean and reassemble. It's really easy and
    Philip Nasadowski, Sep 30, 2004
  7. I just posted this reply in a similar post, but I had the same problem and
    gave up trying to have the dealer solve the problem (4 trips and not once
    could they fix it). The first thing I noticed on mine was the ground was
    a little loose so I started by cleaning it and tightening it. Didn't help
    much, still there. Next thing I did was removed the rubber boot on the
    cable end for the ground, it seemed like the rim around the face makes it
    hard to get a good connection. You can trim the ring down with a razor
    blade but if you're not careful you'll end up removing it anyway.

    Next I put in a second ground strap (using 4 gauge wire) from the motor to
    the chassis, using the same mount point on the motor and picking a new spot
    on the chassis after cleaning it to the bare metal. I also ran a second
    ground from the battery to the chassis and a second ground from the
    battery to the motor (I was able to do this with a slightly longer bolt in
    the battery, not to long or you'll crack the case. I also removed that
    rubber boot like mentioned before so it worked out better). After all
    these were checked for continuity, I cleaned the ground block which is
    behind the left headlight. Finally I sprayed all the connections, motor,
    chassic, and ground block (not the battery post) with some gloss black
    spray paint, this slows any corrosion and rust from forming.

    Yeah, this seems a little drastic having all the ground connections, but I
    also have a high end stereo system and this helps eliminate noise. You may
    be able to get away with a second ground from chassis to motor only. The
    extra grounds may also help eliminate any ESD fluctuations that can occur,
    which I believe was also happening to me when it was raining and wet
    outside. It's a cheap and easy fix (any automotive parts store should
    have pre-made ground straps for cheap).
    SuzukiChopper, Oct 11, 2004
  8. sorry, one last thing, when checking the charging system, it should be
    atleast 13 at idle, and will reach around 14.6v when you rev the engine.
    Once you hit 1000rpm you should see it reach 14.6 and should not drop or
    go much higher. If it drops when you rev the motor up further you're
    voltage regulator isn't doing its job and should be replaced.
    SuzukiChopper, Oct 11, 2004
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