1GM10 electrical problem

[Gixer]

After motoring for 45mins or so I shut the engine down using the stop handle. Usually I then hear the oil pressure alarm until I turn the key off on the panel. I went down below to find the panel dead, I tried to restart the engine on the button but nothing, everything else was fine except the panel. I took everything apart and check connections to no avail. I was just about to make a call for assistance and the panel started working all on its own.
when back on my mooring I tried to replicate the fault but obviously it wouldn’t do it again….
I’m guessing an electrical fault somewhere but would like some advice.

 

[andsarkit]

Use a multimeter to trace power from the battery + to the output of the ignition switch.
Usual problems are either the fuse connections in the wiring harness or a faulty switch.
Intermittent problems are the worst as you can never be sure you have fixed them unless you find an obvious fault.

 

[DinghyMan]

If your installation is anything like ours was then check the fuse holder and fuse that is in the loom near the starter motor, it corrodes away and cases issues

 

[jamie N]

In my experience with issues like this, it's not unusual to cure a problem by simply 'breaking and remaking' a connection when it's in a slightly harsh environment, such as a boat.

 

[Boater Sam]

Check both end plugs and sockets of the loom extension cable.

 

[Gixer]

Thanks guys, I’ll disconnect everything and use contact cleaner before putting back together. I’ve never looked at the fuse, not sure where it is but I’ll have a look by the starter like you suggest. I know it’s expensive but I’ll buy a new ignition switch from Yanmar as well.

if it happens again could I short the starter to get the motor going again? I’ve seen it done on YouTube but never actually tried it…

 

[VicS]

Thanks guys, I’ll disconnect everything and use contact cleaner before putting back together. I’ve never looked at the fuse, not sure where it is but I’ll have a look by the starter like you suggest. I know it’s expensive but I’ll buy a new ignition switch from Yanmar as well.

if it happens again could I short the starter to get the motor going again? I’ve seen it done on YouTube but never actually tried it…

If you do need to replace the key switch you should be able to get a suitable one from Furneaux Riddall for a lot less money.
Ignition Switches

Yes you should be able to short the terminals on the starter solenoid but remember if the panel is dead your warning lights and buzzer will not be working. The alternator probably will not start to generate either.

 

[Tranona]

Very common problem. The loom, connectors and fuseholder are poor. You will soon find the fuse because of the bulge in the cable.

 

[Gixer]

If you do need to replace the key switch you should be able to get a suitable one from Furneaux Riddall for a lot less money.
Ignition Switches

Yes you should be able to short the terminals on the starter solenoid but remember if the panel is dead your warning lights and buzzer will not be working. The alternator probably will not start to generate either.

Thanks, this would be a ‘get me home’ situation so not to worried.

 

[andsarkit]

Unless you really need a key you can use any on/off switch with a suitable rating that fills the hole.

 

[dukeofted]

Could be a bad engine earth connection, that can cause the whole panel to stop working. Or the crap in line fuse as already mentioned. If it’s the earth you wouldn’t be able to jump the starter.

 

[Gixer]

Could be a bad engine earth connection, that can cause the whole panel to stop working. Or the crap in line fuse as already mentioned. If it’s the earth you wouldn’t be able to jump the starter.

Thanks, I didn't think of that.
I'm sure my volt meter was reading 14 volts when the engine was running so the alternator was working. Could this still be a bad earth or would that stop it from charging?

 

[Tranona]

Poor negative connection is another common weakness with 1GMs. Just go through every connection and check for cleanliness and sound connection.

 

[dukeofted]

Thanks, I didn't think of that.
I'm sure my volt meter was reading 14 volts when the engine was running so the alternator was working. Could this still be a bad earth or would that stop it from charging?

To be honest it doesn't sound like it is the earth from the symptoms but it is worth checking anyway as they do corrode away and aren't easily visible. Usually with earth strap corrosion you would have starting trouble (slow turn over or clicking from the solenoid) before you noticed other electrical bits not working. I'm betting it is something to do with the in line fuse holder but making and breaking every connection is pretty much guaranteed to either fix the problem or reveal the issue.

This is the first wire to check imo:

 

[Gixer]

I owe you all a beer!

It was the fuse holder. I turned the buzzer on and shook the fuse holder and the buzzer became intermittent. Took it all apart, cleaned with contact cleaner and sand paper. Now totally fine.

Thanks again guys