Hi,
Can someone hit me with some knowledge???

Because all I've done over last couple of months is fix things on my boat (hatches, windows, toilets etc), I thought should run my diesel (Nanni 3.90HE) while I'm tinkering.

But when the time came to shut her down, the stop switch didn't work. Had turn off the fuel line. Google's telling me its probably the solenoid. Though I don't know much more than that.

I can add that my control box,which is out in the cockpit, was quite damp from the recent showers.

Any advice?

Thanks.

My advice is to enjoy the process . It might just be switch or the wiring/connections to the solenoid.

This is a basic start stop circuit not off your motor but comonly used .Buy your self a test light and a $40 multi meter and test for power along your stop circuit

If there is a stop solenoid I imagine that you should be able to hear a click from it when the stop button is pressed.

Maybe if you go below and listen carefully to the solenoid area and get someone to press the stop button on/off to check.

I had a look on the net.

Here is the wiring diagram

www.peachment.co.uk/wp-content/uploads/2013/02/Wiring-Diagram-2.60-3.90-4.110HE.pdf

There is a stop solenoid. Its item F on the drawing. If its ground wire was O/C it wouldnt work. Check that too.

Thanks for the feedback. I was thinking the switch and solenoid were one unit. I'll get the multimeter out.

Re enjoying the process: trying to. Kids (my other hobby) take up most of my time. I don't have much time available and every time I step aboard something breaks.

Clean and dry out your control box so that it is free of any moisture/dirt etc.

As HG mentioned, get a multimeter and:
1) Check you have 12v to one side of your stop switch with the ignition on - if you do, press the stop in and make sure you now have 12v to the other side of the switch (switch works ok) - If not work your way back to the 12v supply. Alternatively, turn ignition off, set multimeter to "ohms" (resistance) connect leads to each side of stop switch, press stop in and the reading should be almost 0, the same as if you shorted the leads together. If the reading isn't 0 (or near to it) your switch is u/s or needs attention.
2) If the switch appears to be working with the ignition on, press it in and you should now have 12v to the stop solenoid which means the solenoid should be activated and trying to shut off the fuel rack which will stop the motor. If it doesn't appear to be activated, it may be burnt out and need replacing. If the electrical side of things seems ok, check the mechanical aspect of the solenoid: has a locating pin come off, broken pins or rods etc?

12 volt systems are renowned for failing due to bad earths, moisture ingress and volt drops. Clean everything up free of moisture and oil etc etc.

Apologies if I'm telling you how to suck eggs but not sure how mechanically minded you are!

Best of luck.

Thanks NowandZen. Handy info. And no, you're not telling me stuff I already know. I' do most things myself, but I'm new to diesels and electrics.

Select to expand quote

2loneswordsmen said..
Thanks NowandZen. Handy info. And no, you're not telling me stuff I already know. I' do most things myself, but I'm new to diesels and electrics.

There is a few good books relating to Boat electrics One comes to mind is Don Casey "Sail Boat Electric simplified" there are other but that one comes to mind

They would be on ebay as well as other places
Some one else may give you some other Titles

Don Casey has a series of books with sail boats in mind

Hi
this happened to with my Bukh
the connection to the solenoid had come adrift!
dont despair

On a bukh motor before you switch the ignition off you stop the motor as the soleniod is normaly open and it has to have power to shut te fuel off
Perhap your motor may be like the bukh
It was origianlly set up like that as there fitted in life boats on ships
The bukh will run till it has no fuel left no power needed

Select to expand quote

2loneswordsmen said..
Hi,
Can someone hit me with some knowledge???

Because all I've done over last couple of months is fix things on my boat (hatches, windows, toilets etc), I thought should run my diesel (Nanni 3.90HE) while I'm tinkering.

But when the time came to shut her down, the stop switch didn't work. Had turn off the fuel line. Google's telling me its probably the solenoid. Though I don't know much more than that.

I can add that my control box,which is out in the cockpit, was quite damp from the recent showers.

Any advice?

Thanks.

I always shut my engine down by hand on the fuel control lever. Cables break and solenoids cease performing. Keep It Simple Sailor.