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  1. #1
    Seaman
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    Default temp alarm at idle only

    2008 4.3 L alpha one

    The temp alarm goes off sometimes when I am in Neutral or at low idol. Once I get up to about 5 mph the alarm shuts off. The temp gauge reads normal.

    Any ideas of where to begin? If the impeller was bad I would not think the alarm would not go off at higher speeds. Maybe the thermostat?

    In full disclosure I did install the battery backwards (idiot) and blew the fuse on the starter solenoid and replaced it. Could I have screwed up something else?

    Thanks

    Andy

  2. #2
    Lieutenant Junior Grade
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    Default Re: temp alarm at idol only

    The alarm circuit should have been open when you put the battery in. Dont think that hurt it.
    rebuilding 3 classics
    17 Irvette I/B CC 99%
    20 Shamrock I/B Pilot house. 50%
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  3. #3
    Moderator Bondo's Avatar
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    Default Re: temp alarm at idol only

    Ayuh,... Change the Impeller...
    That's the 1st place to look in Any overheat situation...
    Any Grease is Better,..... Than No Grease at All.......

  4. #4
    Honorary Moderator Emeritus Don S's Avatar
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    Default Re: temp alarm at idol only

    The temp alarm goes off sometimes when I am in Neutral or at low idol......... The temp gauge reads normal.
    Get one of those IR Temp guns and when the alarm sounds, aim the gun at the base of the temp alarm switch and see what the reading is.
    If the gun agrees with your temp gauge and there is no overheat, the switch may be defective.
    Don S.


    Please, no PM's (Private Messages) regarding boat/engine problems.
    That is what the forums are for.
    Only forum/moderator issues will be answered in PM's.

  5. #5
    Seaman
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    Default Re: temp alarm at idol only

    So I changed the impeller, how do I tell if it was bad? It looked to be in good shape. I was not cracked and was there in its entirety

  6. #6
    Honorary Moderator Emeritus Don S's Avatar
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    Default Re: temp alarm at idol only

    Start it up and see if the alarm goes off at idle. If it does, the impeller was not your problem. Did you check that it was actually overheating while using a temp gun?
    Don S.


    Please, no PM's (Private Messages) regarding boat/engine problems.
    That is what the forums are for.
    Only forum/moderator issues will be answered in PM's.

  7. #7
    Moderator Bondo's Avatar
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    Default Re: temp alarm at idol only

    Quote Originally Posted by gazelle View Post
    So I changed the impeller, how do I tell if it was bad? It looked to be in good shape. I was not cracked and was there in its entirety

    Ayuh,... Unless the fins were reasonably pliable, 'n self straightening,...
    It wasn't a wasted effort, whether it was the problem, or not....
    Any Grease is Better,..... Than No Grease at All.......

  8. #8
    Petty Officer 3rd Class
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    Default Re: temp alarm at idol only

    I do not know about this model, but could it possibly be the oil pressure sending the alarm? Temp gauge reads normal and alarm is only at very low RPM. Oil pressure could be low at idle.
    1997 Wellcraft Excel 19SSX.
    Merc 4.3LX, Alpha 1 Gen +.
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