Difference between revisions of "Engine start CB-Oct2010-outline"

Revision as of 02:06, 8 November 2010

Engine Starting random failure

In October 2010, the engine would not crank sometimes. We probably had some problems earlier, but it became obvious as the month went on. We finally had a case where we couldn't reset a circuit breaker to fix it. We were able to start it using a maintainer's way of cranking the engine over.

30 Oct 2010
See description of functional testing, observations, and some thoughts while under way and experiencing the problem.

02-03 Nov 2010
See report of testing and analysis of some possible failure modes. (Unfortunately, no problems were found, and engine started fine after our two days of testing!)

06 Nov 2010
We have no test/work report yet (as of eve 06Nov); however, we have a verbal report:
The CB was replaced by the new one with "wrong" form factor temporarily.
Since CB is the prime suspect at this time, it must be eliminated as culprit before going forward on other analysis. Also, most workers think the CB is indeed a likely failure point.
(The author believes no more analysis/testing was performed today. TODO: verify this statement.)

07 Nov 2010

• Main battery upper switch knob crumbled when we turned it on; switch became unusable. We moved some of the wires so that bottom switch now selects battery #1 and/or #2 or none. Top switch is still in position.
  See sketch and discussion of this fix.
• With above fix, we changed the wiring such that we may have less voltage drop produced for the 12-volt circuits.
• Test sailed the new CB: fairly stiff winds, some seaway to shake the boat around a bit. Performed the "glow-plug" test several times on both tacks: CB never tripped.

TO DO: (informal list 'til we get organized)

• Locate replacement CB in case we find it's failing
  • Have electrically equiv one aboard from West Marine - very different form-factor from original
    Installed it temporarily 06Nov
  • Torresen has located one that appears to fit in current location on engine
    "Volvo Penta p/n 841178, descript. FUSE, $45.79"
    • Ask Torresen why it says "FUSE"; check p/n with picture info they sent
    • If p/n o.k., ORDER CB from Torreson/Volvo
• Get proper version of engine wiring diagram on wiki (only have camera copy of the good one that came with N'more, wwhich is in the hardcopy engine tech manual), and a nonsense one (still by Westerbeke) from another version of the engine manual.
• Purge our referenes to the bad version of tech manual "Edition two" and make sure we're only using info from "Edition one"