Relay Box VP MD2040

[Erwin Swart]

Hi all,

Started this morning my VP MD2040 engine like a normal procedure, glow for 10 secs and start.
This time it took more time as usual to start the engine.

When going inside my boat I noticed a strange smell like something had been burned.
Looking into the engine compartment I noticed the wiring from the glowplug to the relay box had been completly burned.
Also many other wiring at the relay box were burned too as well the wiring connected to the start engine.

Ordered a new relay box including the wiring though want to understand what had happened.

Would it be the wiring from the glow plugs to the relay box which was maybe damaged and caused the short circuit. If this is the case why did the other wiring burned too?
Could the start engine or alternator cause the problem.

Your thoughts are welcome

 

[Kinsale373]

I just had a quick look at the wiring diagram in the Workshop manual. I think that the starter motor relay and the glow plug relay are in the same relay box or board. So the problem could be with either circuit.
I think it would be worth taking off the starter and have it checked by an Auto Electrician or someone used to working on them.
Check the Glow Plug circuit for direct shorts to ground. There should be a low resistance between the top of the Plug and Ground -the Engine block. I can't remember the resistance but you'll find it on UTube where guys show how to test the plugs. A direct short to ground would pull a lot of current here and may have caused the melt down. Check for any metal debris or loose parts around the glow plugs or a lot of water that may have caused a short

Kinsale 373

 

[Jokani]

I just had a quick look at the wiring diagram in the Workshop manual. I think that the starter motor relay and the glow plug relay are in the same relay box or board. So the problem could be with either circuit.

Correct, both relays are contained within the same box, both circuits use exactly the same model of relay unit, which is handy as a spare can then be used for either, can also be handy for testing purposes as you can quickly swap them over.

 

[Erwin Swart]

Thanks for feedback
I do have the impression the wire connected to the engine had some fractures and and caused the melt down of the wiring

Though wondering why the fuse connected to the relay box did not protect the melt down of the wiring

Any idea about this?