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    Dead in the water

    getting ready to head out today, turned the key, heard the loud Merc beep and the went to start.... nothing now I don't even get a tone when I turn the key.

    Voltage at the battery is 12.8v, Voltage at the ignition switch is 2.6??

    I checked the engine breaker and it wasn't tripped (I read 2.6v there as well)

    I'm guessing a short somewhere but I'm not really sure where to start looking or how...
    1998 Bayliner 2858
    7.4L MPI / Bravo III
    Harbour Village Marina - Kenmore WA

    #2
    Not a short....most likely a high resistance connection.

    Loosen and tighten connections you can access....big ones and small ones

    Unplug. inspect, reinstall plugs

    Wire brushing surfaces may also help

    A true short circuit will blow a fuse/trip a breaker or drag the voltage down to zero
    Present Boat- 2018 VR5 4.5/200hp Mercruiser
    Last Boat- 1998 Capri 1950CL 3.0 Mercruiser

    Comment


      #3
      Disconnect the 10 pin plug on the engine harness and inspect/clean the contacts then reinstall and try again.
      1997 Silverton 362, 7.4 Crusaders
      1997 Maxum 2400 SCR, 5.7LX Bravo II

      Mike

      Comment


        #4
        Battery cables too, both positive and negative cables and at both ends. Negative at the engine block is a common one that gets corroded then starts to fail.
        Dave
        Edmonds, WA
        "THE FIX" '93 2556
        Carbureted 383 Vortec-Bravo II
        The Rebuild Of My 2556 https://www.baylinerownersclub.org/f...76?view=thread
        My Misc. Projects
        https://www.baylinerownersclub.org/f...56-gctid789773

        Comment


          #5
          Checked all the batter terminals, Checked the big engine connector, it looks clean and well connected. Voltmeter shows 12v at the battery switch, 2.7v at the engine breaker, the only thing between those is the starter. Tomorrow I'll try to get a voltmeter down there...

          when I turn the key, the gauges don't even wiggle, which is strange because they were fine before.. when I first tried to start it everything was normal until I tried to start it. Is it possible that the starter motor just gave up the ghost in that instant? (without even a horrible noise to mark it's death) Possible it's just the solenoid?
          1998 Bayliner 2858
          7.4L MPI / Bravo III
          Harbour Village Marina - Kenmore WA

          Comment


            #6
            The engine breaker is fed directly from the positive battery cable via the starter lug. There may also be a block fuse connected at that lug but I believe it protects the alternators charge lead. I’ve read that block fuse can get connected incorrectly.
            Click image for larger version

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            Dave
            Edmonds, WA
            "THE FIX" '93 2556
            Carbureted 383 Vortec-Bravo II
            The Rebuild Of My 2556 https://www.baylinerownersclub.org/f...76?view=thread
            My Misc. Projects
            https://www.baylinerownersclub.org/f...56-gctid789773

            Comment


              #7
              Check your positive cable at the solenoid. Did you happen to check both the battery to switch and the switch to starter cables at the switch?
              P/C Pete
              Edmonds Yacht Club (Commodore 1993)
              1988 3818 "GLAUBEN”
              Hino EH700 175 Onan MDKD Genset
              MMSI 367770440

              Comment


                #8
                The culprit is corrosion. start at the battery terminals,are the lead posts clean and shiny? Battery cable ends on BOTH ends clean and shiny. A common failure point is steel cable ends and not copper ones.Then to the starter where the main power connection is made. All terminals clean and shiny?.
                From the starter connection to the main CB then thru the harness plug to the helm.

                Comment


                  #9
                  Originally posted by njosephson
                  Tomorrow I'll try to get a voltmeter down there...
                  What have you been using when you got the 12 volt and 2.7 volt readings?


                  I agree with vr5200......
                  "A true short circuit will blow a fuse/trip a breaker or drag the voltage down to zero"
                  a "short" is a short-circuit, meaning that a conductor (of sorts) is taking the current on a short-cut journey.
                  As suggested, you are seeing high resistance somewhere within that circuit.
                  A fully charged 12 volt wet cell battery should offer around 12.4 volts.

                  Mike makes an excellent suggestion with regard to the multi-pin engine harness/hull harness connector. This connector carries all engine data and 12 v power to the helm.
                  These pins rely on a mild friction fit to provide continuity. Often the pins lose the necessary friction fit.


                  Click image for larger version

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                  Another suggestion would be: if by chance the boat is equipped with a Perko MBSS, these are known to have light duty contacts backed by a light weight spring.
                  As Pete said;
                  "Did you happen to check both the battery to switch and the switch to starter cables at the switch?"
                  You could have high resistance caused by the light duty MBSS contacts and/or from a poor cable-to-terminal connection.


                  As for the starter motor giving up the ghost, use your VOM to test for voltage statically and dynamically.
                  With the MBSS making a battery selection, the solenoid's main lug should show 12 volts.
                  The yellow/red stripe circuit should show 12 volts (at the solenoid's S terminal) when the key in the Start Position.
                  Listen for the solenoid to make a "clicking" sound!



                  .
                  Rick E. (aka RicardoMarine) Gresham, Oregon
                  2850 Bounty Sedan Flybridge model
                  Twin 280 HP 5.7's w/ Closed Cooling
                  Volvo Penta DuoProp Drives
                  Kohler 4 CZ Gen Set

                  Please, no PMs. Ask your questions on forum.

                  Comment


                    #10
                    A nights sleep makes such a difference. I missed that the multimeter was just floating,not really showing 2.7v (I think it was auto ranging into ac volts). So I switched gears and started tracing continuity instead.

                    Battery - to engine block = good
                    Battery+ to switch= good
                    Switch to engine breaker= nothing across engine breaker = good

                    So it seems like something between the switch and the engine breaker is a problem, starter solenoid maybe?

                    Before I inject myself into the tiny space available to be able to look at the starter, I'm going to go home and get a couple of alligator clip leads so I can test stuff with the one hand that I can get in there. One diagram I found shows a 90 amp fuse back there ( https://images.app.goo.gl/GRwpxZkPW65oEkpAA -- great place for a fuse by the way). that would at least explain the issue but then the question is how the hell did I blow that sucker...

                    I might also try and bypass it to see it the rest of the system (gauges etc) can power up without it.. (probably better add a fuse on that test lead ..)
                    1998 Bayliner 2858
                    7.4L MPI / Bravo III
                    Harbour Village Marina - Kenmore WA

                    Comment


                      #11
                      Caution......there are many cases where simply doing an ohms check on a circuit may not reveal the degraded/corroded connection.

                      Obviously if it is really messed up the number will be improper..............and in many cases a visual inspection will confirm a physical defect of some kind.

                      But there are many instances where a simple ohms check may not display a number that is alarming.

                      You might want to actually load the circuit in question with a modest sized incandescent bulb to narrow down which circuit has the high resistance.

                      I genuinely hope you find an obvious problem quickly......but if not....doing voltage checks on a loaded circuit in a dynamic operating condition is the best way to identify a circuit that is not capable of passing the normal amount of current.

                      The rule of thumb us that each side of the circuit is allowed to drop .5 volts.

                      In some cases, it means you may need to construct a very long jumper so your meter can read the entire circuit from end to end.

                      I have no idea about the level of your electrical troubleshooting experience, but you seem to own the right tools and are eager to dig into the project.
                      Present Boat- 2018 VR5 4.5/200hp Mercruiser
                      Last Boat- 1998 Capri 1950CL 3.0 Mercruiser

                      Comment


                        #12
                        If you have voltage at the breaker the fuse on the starter solenoid is good as it provides power to the breaker. Again I suggest you check the harness 10 pin connector.
                        1997 Silverton 362, 7.4 Crusaders
                        1997 Maxum 2400 SCR, 5.7LX Bravo II

                        Mike

                        Comment


                          #13
                          No power at the breaker (either side), Power at the switch, going to go back tomorrow with a longer jumper and crawl down and test the breaker at the starter
                          Thanks ti everyone for the helpful advice, I'll post back here once I've gotten back to the boat and done some more investigating.
                          1998 Bayliner 2858
                          7.4L MPI / Bravo III
                          Harbour Village Marina - Kenmore WA

                          Comment


                            #14
                            Originally posted by njosephson View Post
                            No power at the breaker (either side), Power at the switch, going to go back tomorrow with a longer jumper and crawl down and test the breaker at the starter
                            Thanks ti everyone for the helpful advice, I'll post back here once I've gotten back to the boat and done some more investigating.
                            Ok with no power at the breaker the fuse would be the next thing to check.
                            1997 Silverton 362, 7.4 Crusaders
                            1997 Maxum 2400 SCR, 5.7LX Bravo II

                            Mike

                            Comment


                              #15
                              Okay, the mystery gets deeper. I'm back at the boat with a plan on searching for short circuits and bad connections. Read a bunch about failed slave solenoids and I'm thinking the issue might be in the vicinity of that. ... but I start at the ignition switch and.... it's hot, wtf? THIS WAS DEAD YESTERDAY. crawled down and checked the starter motor fuse, both sides are hot...pull the plastic cover off and check the engine breaker, 12v both sides...

                              On a side note the slave solenoid is hidden UNDER the mercathode box...

                              Going to try to start it up and then maybe just replace the slave solenoid in the hope that this was the cause.

                              okay so it started just fine...old boats are weird!!!
                              1998 Bayliner 2858
                              7.4L MPI / Bravo III
                              Harbour Village Marina - Kenmore WA

                              Comment

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