Dead Thetford N3000 fridge Warwick XL

The on/off switch is inoperative, and the fridge appears dead.
The fuse in the box behind the driver's seat is ok.
It was last used (all ok) first week of April.
The van is hooked up at home - supposed to be going away tomorrow.
PLEASE HELP!! 
TIA
Keith

The fridge control panel is powered by a separate 12v cct. I assume you have the same EC500 as I have, mine is fuse number 5 on the front of the EC500.
Failing that, if competent, you can check the voltages at the back of the fridge by simply removing a fridge vent (well you can on my Symbol, not sure about your Warwick).

Thanks Dbvwt. I have checked all the fuses - all ok. I will look at the power at the rear. 

If I remember correctly, on the back of the fridge there is the mains input (easily recognisable because of the cable size), a high current 12v input (from the alternator while driving) and a low current 12v input which is the control panel voltage I mentioned earlier.

Here’s the diagram with wiring colours, hope it helps. 

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You have got the 12V habitation powered up I’m assuming. Sorry to mention it but in the heat of the moment when faced with a problem it’s easy to overlook the otherwise obvious things.

Here’s a picture of the rear of our N3000 series fridge with the cable cover removed (from memory it’s just one screw to remove, should be obvious). You can see the connector just right of centre in the image with the purple and black cables which is the low current 12V feed that supplies the fridge control board and display, referred to in the circuit diagram above. Check that this connector isn’t loose.

If your multimeter has fine enough probe tips you should be able to get them into the connector to check whether the 12V is present. If you find you have 12V present then it’s likely that the control board or display board has a fault. These are usually supplied as a pair in Thetford’s spares system. 

The control board (which is what all those connectors plug onto) has a glass fuse on it that you could check if you feel able to remove the board. Not easy given the access through the lower vent, but possible.
For your safety I recommend you do the above checks without EHU connected.

Tim



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Many thanks to both Dbvwt and Tim. I had got as far as looking at the wiring through the lower vent, but not as far as seeing any fuse on that board. I will have another try now I know a fuse exists. I have my fingers crossed! Thanks again guys, I will report further.