Engine advice

[hagrid]

Last weekend my port rev counter started to have a fit, I used the good old Seatstart and they corrected the problem, the Alt belt was loose, I got under way... The following day I started the engine and the alarm went off, with the battery symbol flashing. I then restarted it a couple of moments later same thing, I was now getting worried.... I then started for the third time and hey presto everything A OK.

A little while later I see my instruments that are running off the port engine have gone off, I then restart the engine and hey presto all is fine again.. what do i need to check?

regards

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[Deleted User YDKXO]

I'd like to know the answer to this question as well because one of my engines is exhibiting the same symptoms albeit now permanently ie. charging light on (at idle, goes off at high rpm), batteries discharging, upper and lower tachometers failed
A new alternator has been fitted and the belt is tight. Also the batteries are new. What is the connection between the tachometers and the alternator?

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[DavidJ]

The problem has a nasty intermittent electronic ring about it. On my KAD 43's I've got an electronic box on the top which is RPM control. If your KAD 42's has the same, swop them over and see if the problem swops.
Bit of a bind to swop the alternators over but that would be my next move.
Hopefully others may provide a more logical solution.
David

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[burgundyben]

On some engines the tacho picks up its signal from the alternator.

Usual checks of connections, including how tight the female spades in the multi plug on the back of the alternator I should think.

<hr width=100% size=1>I didn't knacker TCM's copper it was Trazie

 

[hagrid]

When Seastart came over they said the Alternator runs the tachos so that would indicate some kind of electrical issue, I have no idea where to start but will try...



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[Questor]

Hagrid

Re our conflab about this yesterday, and having thought a bit more about it, if it were a dodgy isolator switch, then you wouldn't be able to start the engine, although all the other symptoms could point to that being the problem.

Possibly could be down to just a bit of corrosion, or bad earth / contact. Easiest cure would be to out it and buy the Phantom!

R

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[hagrid]

Agreed have engine fault well not really but good enough excuse for SWMBO, so must buy new boat...... Phantom? or Azimut? like the look of? an seeing one soon



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[Moose]

Check the belt hasn't loosened again.

<hr width=100% size=1><font color=green>Toscana is for sale!</font color=green>

 

[Roy]

Happened to me three weeks back on Kad32s. Slipping belts now renewed were part of another problem but the rev counter loss and flashing battery warning were indicating an alternator fault or shot diodes in alternator. What it actually turned out to be was a loosened spade conn at the alternator - just as suggested on this thread.

<hr width=100% size=1>What does this mean then?

 

[hagrid]

Many thanks will go take a look see tomorrow well its better than work..... will advise


Andy

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[nictbrown]

Hagrid
Have been through this sort of thing with KAD42s, and agree above. As mentioned strongly suspect alternators, but I also had vibration pull one engine loom plug out - this plugs in where the relay for the compressor is on top of the engine. First thing is unscrew these and check they are clean refix and make sure there is enough play in the loom cable and lash it to something on top of the engine to hold a bit of slack so the pull is not on the connector. Next on alternators - assuming they are sound ie regulators, brushes and cable fixings ok (check undo redo after cleaning) it may be excitation. To wake this up take a short piece of wire and briefly 'flash' the output to the charging light (the D terminal), and a 12v supply which is conveniently at the alternator on the field terminal (usually a separate feed on dual engine boat engines). By flash I mean connect for about 3 seconds. Also possible is ground/negative connections. Most marine alternators have a separate ground connection, but KAD42 take it straight to the engine block and through the connection at the back of the engine.

If this does not fix you have of course the wonderful option of substitution having 2 engines. If one side works I would suspect alternator on the other. It may seem tedious but you can probably get it down to 15 minutes or so to swop over. You can usually also swop over connections to the back of the tachos to eliminate instrument error (but this is unlikely to be the problem).

Good luck.

<hr width=100% size=1>Regards Nic