Unknown component on Yanmar engine panel

[Alex_Blackwood]

Some info on Vishay Thin film Non resettable fuses.
Fuses | Vishay
I hear what others are saying and first thoughts were that it was not a fuse. However looking at the diagram, I will reiterate that there is no diode in the charging light circuit. There can't be, current has to flow both to and from the alternator for it to work! The fact that the charge light lit when the device was shorted may in its self be misleading. Do the other lights illuminate as normal or not? Do they work only if this device is shorted? It maybe that the temp. sensor would need to be "shorted" to test. As for using a multi meter on continuity as suggested in #12. As I have previously said if the component is in circuit you can get misleading readings through other components.
Sorry I can't be of more help in IDing the device but almost impossible online.
I also suspect that some posters are not reading what has already been posted.

 

[whatsnormal]

Component identified I think - Rich T suggested I test the other one and when I did I realised it gives different forward resistances depending on the meter settings. Non conductive with meter set to 200R and 2k, 5.26k on 20k, 24 on 200k, 165k on 2000k. Switched to diode mode on the meter (should have thought of that) and they both show a forward drop of around 0.6 volt which I think identifies them as diodes. Unfortunately, I think it also indicates that they’re working fine and not blown, so its back to the drawing board on why the LED doesn’t light up. Thanks everyone; I’ll report back when I get the bottom of it.

 

[VicS]

It looks like this (not a perfect pic sorry - I didn't know I'd be using it for this purpose when I took it.): looks like a type C to me?

Agreed .

 

[Alex_Blackwood]

Agreed .

These things are very difficult to sort out online without seeing the actual units. The OP seems to have, with help from VicS identified the unit as "Type C"
the diagram I sourced for a "Type C" shows that the charging lamp is a filament bulb 12V 1.7W. The OP has LED's This can make a difference to the components fitted to the PCB so the diagram is not much use Just hope the OP has some success in fixing the problem and lets us know how he gets on. Good luck!

 

[ProDave]

Just because the LED does not light up, does it or does it not charge?

Don't rule out the LED being dud.

 

[whatsnormal]

Just to conclude: I don't think this is a yanmar pcb at all, I think its some kind of aftermarket board (there are similar ones on ebay right now). Even more confusingly, I took a close look at the back of the alternator and realised the earth studs weren't connected to the engine block. Added a wire for that and now the charging light comes on but disappointingly it still doesn't charge. I'm assured it used to charge, but I can't see how. Never mind: I've managed to contact the people who originally installed this engine so hoping they will have a clue whats going on. Thanks again to everyone here.

 

[Alex_Blackwood]

Just to conclude: I don't think this is a yanmar pcb at all, I think its some kind of aftermarket board (there are similar ones on ebay right now). Even more confusingly, I took a close look at the back of the alternator and realised the earth studs weren't connected to the engine block. Added a wire for that and now the charging light comes on but disappointingly it still doesn't charge. I'm assured it used to charge, but I can't see how. Never mind: I've managed to contact the people who originally installed this engine so hoping they will have a clue whats going on. Thanks again to everyone here.

I Think that may account for the confusion with the components shown on the diagrams. Thanks for the info!