Re: T&T: Elec issue-one engine no DC power or guages
Tom,
On my old technology Cummins, the B+ battery feed for the engine controls and monitoring instruments originates at the starter motor on the engine. It comes up through the start switch (and normally-closed “Stop” push button), and then feeds the on-engine sensors and the two nav station instrument panels.
However, one symptom you have is different than I would have with a total B+ battery power loss. One of my on-engine controls is the fuel solenoid that’s located in my injection pump. The boat complies with 33 CFR 183.568, so my solenoid needs B+ from the battery to keep it powered and keep fuel flowing. (Cummins does have a solenoid that only needs B+ to shut it off, but that one does not comply with the CFR.)
Anyway, if you have such a solenoid, and your engine DID NOT shut down, you didn’t have a total power loss. That knowledge might help you with further analysis/diagnosis.
One more thing. If you did lose power to your on-engine control and instrument circuits, you would have lost the monitoring alarms for low oil pressure, loss of raw water injection (high exhaust gas temperature) and engine overheating.
Your engine wiring may not be the same as mine, but I have attached a circuit diagram of my on-engine controls and instruments. It might give you some ideas. The B+ distribution is shown in red. The fuel solenoid I mentioned above is on terminal #8 of the engine terminal strip, together with the feed for the voltage regulator.
Hope this helps,
Jim
Peg and Jim Healy aboard Sanctuary, southbound at Daytona Beach, FL
http://gilwellbear.wordpress.com http://gilwellbear.wordpress.com/
Monk 36 Hull #132
MMSI #367042570
AGLCA #3767
MTOA #3436
On 11/16/2014 06:43 AM, Jim Healy via Trawlers-and-Trawlering wrote:
... The boat complies with 33 CFR 183.568, so my solenoid needs B+ from the battery to keep it powered and keep fuel flowing. (Cummins does have a solenoid that only needs B+ to shut it off, but that one does not comply with the CFR.)
Jim, this CFR is not talking about on-engine stop solenoids. The
solenoid required by this section must either be at the tank outlet, or
above the level of the top of the tank. If the engine's fuel inlet is
already above the level of the top of the tank, then the solenoid is not
required at all, per 183.568(a), unless the fuel line itself is routed
above that level. This section also talks explicitly about "carburetor
inlet" and so is primarily targeted at gasoline systems.
So if you have an on-engine stop solenoid which is lower than the top of
the fuel tank, it does not comply with this statute, no matter which way
it works. FWIW.
I know this is a bit off-topic, but I had visions of listees suddenly
worried about some obscure federal rule that only applies to
manufacturers...
-Sean
FWIW, 33 CFR 183.568 is applicable only to gas powered engines, not Diesel.
Ref: 33 CFR 183.501
Applicability.
(a) This subpart applies to all boats that have gasoline engines, except outboard engines, for electrical generation, mechanical power, or propulsion.
-al-
Viking Star
45' Monk Sr. / McQueen
mvVikingStar.blogspot.com
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However, one symptom you have is different than I would have with a total B+ battery power loss. One of my on-engine controls is the fuel solenoid that’s located in my injection pump. The boat complies with 33 CFR 183.568, so my solenoid needs B+ from the battery to keep it powered and keep fuel flowing. (Cummins does have a solenoid that only needs B+ to shut it off, but that one does not comply with the CFR.)
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