After 3 weeks away I gave MB a bit of attention today. The bilge was dry, no rain, and everything seemed in order. The engine started after a second or two cranking so I took her for a good hour or more run on the engine.
I ran all the systems and all was good. 5.8kts downwind and 4.8 upwind. Not bad with a none too clean prop.
I was by then busting for a leak so a quick check that the electric toilet was working. Press the button, Nothing.
Check all the switching and start the engine to make sure there was sufficient grunt, Nothing.
Leak over the side!
Test voltage at the switch. 13.3v.
Test voltage entering the pump. Around 6v.
Trace the wiring back and find all this black goo soaking in a jelly like substance where I store toiletries.
A hand cleaning gel bottle had leaked all its contents and the insulation on the wiring, power and earth, had disintegrated and was the source of the goo.
Cleaned it all up and had 6-12"of bare wire. They weren't touching, I think, but I figured my problem was there. I bought a few metres of 45 amp wire and connectors so will replace it when I can.
I don't know why the resistance was such as to halve the voltage getting to the pump but can't see another cause. Why wouldn't bare wires still get the current through if they aren't physically touching each other?

saintpeter said..
Climate change will do that.

I put it down to Tony Abbott and the Donald. Need something irrational to explain it!

MorningBird said..

saintpeter said..
Climate change will do that.

I put it down to Tony Abbott and the Donald. Need something irrational to explain it!

You have to stop using Donald's Own brand hand cleaner, it turns anything and everything into a gooey mess.

I would never have imagined that hand cleaner (and probably other detergents ) could degrade wire insulation.
Another little thing to look out for.

Well ya learn something everyday.

I was under the impression that electrons flow on the outside of a conductor/wire.
Just checked with mr google and that is true with AC but with DC they travel through the whole wire.
Basically his will mean that if half the wire (ie the outside) is degraded (by corrosion etc) the resistance of the wire will be increased.
Therefore reducing the supplied voltage.

www.quora.com/How-does-electricity-travel-along-a-wire-Does-it-pass-through-the-inside-of-the-wire-or-along-the-outside-of-the-wire

Gary

Yara said..
The hand sterilized was maybe one with alcohol content. The goo could have created a partial short circuit, and hence the reduced voltage at the pump.

I think that is the answer. The bare wires were coated in the goo. I will do the repair on Tuesday and see how I go.