Westerbeke 8.0 BTDA kicking my arse

Discussion in 'Electrical Stuff' started by ZZ13, Dec 11, 2020.

  1. ZZ13

    ZZ13 Well-Known Member

    Nov 25, 2009
    Lady's Island, SC
    2001 400 Sedan Bridge
    Cummins 450 Diamond
    This is the wiring diagram from my 8.0 BTDA manual that I am using for debug.
    AF0B8FA1-F9C9-4DDC-B42F-E6BC386AB709.jpeg
     
  2. ZZ13

    ZZ13 Well-Known Member

    Nov 25, 2009
    Lady's Island, SC
    2001 400 Sedan Bridge
    Cummins 450 Diamond
    Fixed it! Error by yours truly. This generator has two oil switches. One for low pressure shutdown and an auxiliary for Sea Ray system monitor alarm. I had analyzed the auxiliary had gone bad, bought its part number and replaced it. But noooo! After tracing wire colors it was the shutdown switch that went bad and I put an aux switch part number in its spot. Jumpered it and runs on and on normally now. The two switches are different so gotta go buy the right one. Now he has a spare aux oil switch. Ha!

    Also I discovered the power runs serially through both the on generator stop switch and the remote panel start/run switch. With the remote panel switch off, that creates an open circuit. You have to put it in the run position for the generator to continue running when started from the on generator switches.
     
    Last edited: Feb 12, 2021
    kvduff, dtfeld and ttmott like this.
  3. ttmott

    ttmott PhD in OCD TECHNICAL Contributor GOLD Sponsor

    Apr 3, 2012
    Space Coast Florida
    2006 52 Sedan Bridge
    Cummins QSM11
    Those were some of my discoveries also and the reason I drew up the schematic - not in the SR drawings nor the generator drawings; at least for the 400DA.
     
  4. LMBoat

    LMBoat Active Member

    492
    Oct 4, 2006
    Ft Lauderdale
    1999 450 EB
    Cummins 6CTA's
    Great tip on the 2 oil pressure switches! I have seen them, and wondered why. Thanks for the teaching! This will be good to know for future troubleshooting.
     
    dtfeld likes this.
  5. ZZ13

    ZZ13 Well-Known Member

    Nov 25, 2009
    Lady's Island, SC
    2001 400 Sedan Bridge
    Cummins 450 Diamond
    The one with the thicker white wire going to it is the shutdown sensor. You’ll probably need to scrap the red paint away from the wire to see it. The system monitor switch is a smaller black wire with white stripe.
     
  6. The Bill Collector

    The Bill Collector Well-Known Member GOLD Sponsor

    Jun 2, 2008
    Tacoma, WA
    1998 450 Sundancer, Achilles dinghy
    3126 Cat's
    Thank you guys, great info for that day in the future with my 8.0 BTD
     
    dtfeld likes this.
  7. ZZ13

    ZZ13 Well-Known Member

    Nov 25, 2009
    Lady's Island, SC
    2001 400 Sedan Bridge
    Cummins 450 Diamond
    And the beat goes on...

    I put in the correct oil shutdown switch. That fixed that. After researching it’s normally closed above 10 psi and opens below that. The Sea Ray auxiliary switch is the opposite. Normally open and closes at low pressure. So that explains that.

    Oil gauge has never worked since he bought the boat. Needle just hung limp straight down. Replaced oil sender and that fixed that.

    Temp gauge is pegged to right. Replaced temp sender and no change. So that leads to the remaining problem. All three gauges peg to right when engine is running as if all senders are shorted to ground. When shut off the oil and voltage gauges return to normal off position. But temp gauge stays pegged. And here is the interesting part. With ground cable of generator start battery disconnected, there is still power to the control panel to activate gauges and relays. Seems like there is a short to the boat ground system somewhere. I have some research to do to attack this one.

    Two pictures attached are the gauges with generator running. And with generator in ON position but not started.

    By the way if you need to replace temp sender, remove belt, alternator and alternator tension bracket. So much easier to get tools and hand back there that way.
    AC640F2F-98A8-4AD6-9049-AA162DC428E7.jpeg 98C10BB3-7B7A-4998-B98C-25D2B2B49D93.jpeg
     
  8. ZZ13

    ZZ13 Well-Known Member

    Nov 25, 2009
    Lady's Island, SC
    2001 400 Sedan Bridge
    Cummins 450 Diamond
    I went back to the boat today and I tried every possible combination of disconnecting wires at the gauges. Never got rid of the problem. So I disconnected the ground wire from the gauges and ran a wire direct from the battery (-) to the ground on the gauges. Problem still there. Could it be the battery? It has a real hard time starting the generator now as well. Each gauge reads 12.4v at its power posts with a multimeter. I guess it’s possible all three gauges are bad. Multimeter reads 12.4v at voltmeter while the voltmeter needle is pegged.
     
    Last edited: Feb 23, 2021 at 12:41 PM

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