815 Macerator Pump Power

[will1701]

Merry Fisher 815 (2010)

Hi folks. I am looking for the electrical diagrams for this boat. I can find nothing of use in the owner's manual - there is no detail whatsover. (Note that I am a retired electrical design engineer and so boat systems are "interesting" but not unusual to me).


I have a problem with the masher/macerator pump switch and the associated waste water gauge. In the WC, both the macerator/masher pump switch and the waste water gauge (as shown above) are "dead" - no power. They share a common 12V feed. The unrelated shower pump and all other systems on the boat are good.


When connected directly to a 12V battery, the masher/macerator pump, rated at 12V/16A, operates correctly and discharges the waste tank. Tracing backwards and using a voltmeter, there is no 12V power at the terminal connections at either the masher/macertor pump switch or the waste water gauge in the WC. I can find no blown fuses or tripped breakers further upsteam of the switch and gauge. I have tried this with all systems energised and even with the engine running in case this was required too.

Where do I look next?


Looking at the manuals of similar Jeanneau craft of this age, I can see hints of breakers in addition to fuses in the circuit path. I can find no such devices on the 815. The macerator pump would require a minimum of a 20A fuse or a larger breaker. I can find no such blown fuse or breaker. What am I missing?

I have also emailed Jeanneau service support on this matter.


Will

[Charlie-Bravo]

Well let’s hope Jeanneau come along with the answer.

I would suspect another ‘hidden’ switch / relay / in line fuse, is the breaker for this circuit obvious and identified , and if so I presume you have ruled out a dodgy breaker, they can physically switch, or push and click without actually doing anything.

Failing all else, you sound like fitting a new power line and breakers / fuses wouldn’t challenge you.

Have they recently stopped working? or is this a new to you boat, and you are on the voyage of discovery?

CB

[will1701]

Jun 19, 2023 18:27:57 GMT Charlie-Bravo said:

Well let’s hope Jeanneau come along with the answer.

I would suspect another ‘hidden’ switch / relay / in line fuse, is the breaker for this circuit obvious and identified , and if so I presume you have ruled out a dodgy breaker, they can physically switch, or push and click without actually doing anything.

Failing all else, you sound like fitting a new power line and breakers / fuses wouldn’t challenge you.

Have they recently stopped working? or is this a new to you boat, and you are on the voyage of discovery?

CB

The boat is new to me post winterisation. I’ve pulled all of the spade connectors off the back of the switch and the water gauge. As you say, it’s possible a hidden breaker/relay/whatever in the supply path. In the extreme I can simply run an appropriately power line to the switch and be done with it.

No doubt I’m going to be extremely embarrassed if Jeanneau support come back with something very obvious 🙄

[Charlie-Bravo]

Just a random thought …… being a poo thrasher and pump system , and not that I have experience of these, but I would imagine that things could get very messy if activated with a full loo and holding tank, is there some sort of level switch on the holding tank to safeguard against this , that could be breaking the circuit?  

CB

[will1701]

Found the problem. Under the WC sink, right at the back and almost behind the water tank, there was a two pole (12V/GND) connector which was disconnected (see photo). I tested it with a  voltmeter and it was power. I found the mating end lying on the floor out of sight and discovered it had continuity to the switch and gauge in question.

When reconnected, the water gauge lit up and the macerator could be operated. No issues it would seem.

a) Jeanneau did get back to me with an excellent set of circuit diagrams for this boat. It wouldn't have helped me with this though.
b) Why was this connector disconnected? Presumably by the previous owner whom I'd like to speak to about this. I note that all connectors of this type are cable tied to avoid accidental disconnection. I have since done the same to this one.

[Charlie-Bravo]

Lovely when you find a simple fix ! Well done

CB