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  1. #1
    Join Date
    Apr 2003
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    Eastern Shore, Va.
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    2,311

    Default Troubleshooting The Buzzer

    The warning buzzer on my rig is buzzing again no matter what – even without any trouble condition – as long as the ignition switch is on.

    Is it true that the only sensors/senders that would cause the buzzer to sound would be for oil pressure and engine temperature?

    Since the oil pressure sensor is tough to access (it's tucked up under the back of the exh manifold on the port side) I guess the way to troubleshoot this would be to disconnect the water temp sensor/sender and see if the buzzing continues ... which would mean that at least the oil pressure sensor/sender is bad (and possibly the temp sensor as well)...right?

    I wish I had addressed this while the ex manifolds were off...it's hard to see what's going on with the oil pressure stuff with the manifold installed.

    Question: There were TWO wires for sensors/senders in the vicinity of the oil pump. I forget the wire colors (I think one was light blue?) but does anyone know what those two wires would go to? Maybe one goes to the oil pressure gauge and the other goes to the buzzer...?

    Finally, is there a way to test the oil pressure and engine temp sensors with an ohmmeter? I seem to recall someone discussing that here?

    Thanks for any clues. Why does everything seem to want to break down just when the tuna bite is taking off?

    Engine is a 2000 PCM / GM 350 TBI with RWC

  2. #2
    Join Date
    Apr 2005
    Location
    Havertown, PA
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    Default

    Crunch...

    The senders for the alarm buzzer in the instrument cluster are simple switches that close to ground when the fault condition exists - low oil pressure or high engine temp. Here's the diagram for a PCM engine. Look at the lower right hand area of the diagram for "traditional" wire color scheme. The buzzer circuit should be colored green (or lt. green). The oil pressure gauge color should be lt. blue and the temp gauge circuit should be tan:



    The color for the buzzer circuit at the instrument cluster may change because of the wiring harness extender and could be tan/blue.

    The two buzzer senders can be checked easily with an Ohmmeter. But, since they are connected together, you would have to disconnect one of them before testing. With the engine and ignition OFF, the temp switch should show open and the oil pressure switch should show closed.

    There is one other possibility: There could be a short to ground somewhere along the length of the wire that goes back to the instruments (pinched or abraded wire). If that is the case, the buzzer would sound all the time.
    '98 200 Open
    - SeaMaxx 351 CID Ford, 260 HP, Holley Carb, FWC
    - N39 59', W75 18'
    - LBI, NJ; Upper Chesapeake Bay, MD

    Eat drink and be merry, for tomorrow they WILL make it illegal.

    "We're not lost, Private -- We're in Normandy." : Maj. Richard Winters, Easy Company, US Army 101st Airborne. Normandy on D-Day

    Disclaimer: Any suggestions made in these posts are just that, suggestions. To quote Obi-Wan Kenobi: "Who's the more foolish - the fool, or the fool who follows him?".

  3. #3
    Join Date
    Apr 2003
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    Eastern Shore, Va.
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    Default

    Kurt,

    Thank you very much, as always. That's all the info I need.

    If the temp or oil sensors are bad, does anyone know whether I can use the automotive (non-marine) equivalents for a 350? One online source wants ~ $35 each for them.

  4. #4
    Join Date
    Apr 2005
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    Havertown, PA
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    Default

    Crunch...

    An automotive type oil pressure switch ought to work. I don;t think that there is really a difference between the car part and a marine part (except maybe price). The one on my engine sure looks like the ones that were on my older Broncos.

    I don't know if there is really an "automotive" version of the high temp switch. It's not something you usually find in cars.

    Once you chase down which switch it might be, you could try giving Engines1 a call. They may have them at a better price.

    The other alternative would be SKIDIM. They have the whole kit, both switches and the buzzer for ~$40 (click on image for link):

    '98 200 Open
    - SeaMaxx 351 CID Ford, 260 HP, Holley Carb, FWC
    - N39 59', W75 18'
    - LBI, NJ; Upper Chesapeake Bay, MD

    Eat drink and be merry, for tomorrow they WILL make it illegal.

    "We're not lost, Private -- We're in Normandy." : Maj. Richard Winters, Easy Company, US Army 101st Airborne. Normandy on D-Day

    Disclaimer: Any suggestions made in these posts are just that, suggestions. To quote Obi-Wan Kenobi: "Who's the more foolish - the fool, or the fool who follows him?".

  5. #5
    Join Date
    Apr 2003
    Location
    Eastern Shore, Va.
    Posts
    2,311

    Default

    Kurt,

    Thank you very much. Now the damn thing has stopped buzzing again. I hate intermittent problems!

  6. #6
    Join Date
    Apr 2005
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    Havertown, PA
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    Default

    Quote Originally Posted by Capt Crunch View Post
    ...Now the damn thing has stopped buzzing again. I hate intermittent problems!
    See! It knew you were about to chase it down and it coyly said, "Oh no you don't!" Freakin' Murphy and gremlins...

    Mine stopped working, all of a sudden, last year. It turns out there was a corroded connection at one of the buzzer terminals behind the instrument panel. They'd used plain old crimp terminals on the wires to the buzzer (as with just about everything else back there) and the (+) one was a mess. I replaced both with Ancor heat-shrink style terms. Everything else back there looked fine. Don't know how that one connection managed to get so munged up.
    '98 200 Open
    - SeaMaxx 351 CID Ford, 260 HP, Holley Carb, FWC
    - N39 59', W75 18'
    - LBI, NJ; Upper Chesapeake Bay, MD

    Eat drink and be merry, for tomorrow they WILL make it illegal.

    "We're not lost, Private -- We're in Normandy." : Maj. Richard Winters, Easy Company, US Army 101st Airborne. Normandy on D-Day

    Disclaimer: Any suggestions made in these posts are just that, suggestions. To quote Obi-Wan Kenobi: "Who's the more foolish - the fool, or the fool who follows him?".

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