Glow plug light flashing

[Neil2]

Does anyone know why my glow plug light has just started flashing?  It's an intermittent flash, not a constant regular flash, Nannidiesel 3 cyl ie Kubota base engine.

[Tony Brooks]

Are you absolutely sure it is a glow plug light?

 

Engine running or stationary?

 

Unless it has some fancy relay in the circuit all I can think of is shorting within the ignition switch or glow plug switch or something lose so a live touches the glow plug circuit. I think water in the main multiplug would probably have too much resistance to allow it to happen.

[Chewbacka]

7 minutes ago, Tony Brooks said:

Are you absolutely sure it is a glow plug light?

 

Engine running or stationary?

 

Unless it has some fancy relay in the circuit all I can think of is shorting within the ignition switch or glow plug switch or something lose so a live touches the glow plug circuit. I think water in the main multiplug would probably have too much resistance to allow it to happen.

Could it be the oil pressure light?

[Tony Brooks]

6 minutes ago, Chewbacka said:

Could it be the oil pressure light?

If it is the cable to the pressure switch would have to be shorting to metal or negative intermittently or the pressure switch might be faulty.

[Neil2]

Please don't imply I am a complete idiot it is definitely the glow plug light not the oil light

 

I've never known one to start flashing before, even in a modern car, and my assumption is there must be a short somewhere, but I thought I would check it's not something more sinister.

 

Excuse my short temper, things are not going well at the moment in fact this flashing light is the least of my problems.

[Chewbacka]

2 hours ago, Tony Brooks said:

If it is the cable to the pressure switch would have to be shorting to metal or negative intermittently or the pressure switch might be faulty.

Maybe not this case, but oil pressure lights can flash if the oil level is low, or it’s an old engine with big clearances so marginal oil pressure at idle.

41 minutes ago, Neil2 said:

Please don't imply I am a complete idiot it is definitely the glow plug light not the oil light

 

I've never known one to start flashing before, even in a modern car, and my assumption is there must be a short somewhere, but I thought I would check it's not something more sinister.

 

Excuse my short temper, things are not going well at the moment in fact this flashing light is the least of my problems.

Sorry, did not mean to insult your knowledge, it’s just that I thought most narrowboats didn’t have glow plug lights.

[TheBiscuits]

3 hours ago, Neil2 said:

Does anyone know why my glow plug light has just started flashing?  It's an intermittent flash, not a constant regular flash, Nannidiesel 3 cyl ie Kubota base engine.

Is the relay on it's way out?

[Tony Brooks]

1 minute ago, TheBiscuits said:

Is the relay on it's way out?

If it has a relay but even then I think a simple make & brake relay would be very unlikely to cause a flash but possibly a timer relay might.

 

An intermittent  short to earth can make an oil pressure, charge or overheat lamp flash because they all have a feed when the engine is running - all the time but a glow plug circuit should only have a feed when its switch or relay is turned on so unless the circuit is energised it should not be able to flash. From that it follows that to get a flashing lamp when the circuit is not energised would require a short between the glow plug circuit and another live wire. In my view that is not as likely a member getting their lamps mixed up.

 

Get the manual out and see if you do have a timer relay and if you do I would  suggest that is likely to eb the first suspect.

[TheBiscuits]

If it's got the newer nanni panel where you hold the start button in halfway to preheat then push fully to start it might just be dirty contacts on the button.

 

If it's the older multi position keyswitch type then that could be dirty contacts too.

 

The glowplug light is built into either standard panel, not an optional extra.  It's in a block of warning lamps on the older panels or built into the tachometer dial face on the newer ones.

 

 

 

 

20 minutes ago, Tony Brooks said:

to get a flashing lamp when the circuit is not energised would require a short between the glow plug circuit and another live wire.

I hadn't thought of that - I just assumed it only flashes when in normal use and we all know what they say about assume ...