Mikuni MY30 failure - diagnostic help please

[bobm]

The heater working well, no problems then first symptom was failure to fire up. Next event was that the circuit breaker tripped when at fire up stage, tried a couple more times, same result but then did fire up. Latest symptoms are that on switch on the motor starts, then the fuel pump can be heard ticking away but the unit does not fire up. I thought that this must indicate that the glowplug is at fault but I am not so sure. When the unit is working normally on the control panel there are two lights lit either side on the 3 way switch,(heat/off/air only), the red one for heat and a green light which goes yellow when used in the heat mode - stays green when in air mode. Only the red light now lights up, the green/yellow is out.
Taken in conjunction with the earlier problem whereby the circuit breaker tripped would this indicate a Control box problem and not the glowplug or both?
Any ideas?

 

[seamaster30]

I found this, but it may be worth calling Mikuni.
http://www.mikuniheating.com/images/diagnostics/MY30_faultfinder.gif

 

[steve28]

Could be something as simple as the guaze around the glowplug has carboned up. Also i have my battery feed for the heater through the Ampmeter this is quite diagnostic as to what the glowplug is doing.

Steve

 

[Habebty]

I know it's an obvious thing to say, but is the diesel tank less than 1/4 full. My heater will click away and not fire up if the tank is less than 1/4 as the intake is does not go all the way to the bottom of the tank so you have some left for propulsion.