Over night I have been thinking about why the AUX fuel pump was not working. Today I checked all the wiring to the AUX fuel pump. Positive and negative were correct, earth wiring was OK, I had power to the pump ( 12.5 Volts ), the AUX pump switch worked OK, nothing was reversed. The multimeter got a very good workout to no avail, every thing seemed to be as it should. I decided to do an airline engineering procedure which I have seen many times over the years, it is referred to as a " TT " ( Technical Tap ). I applied power to the pump from an external battery and lightly tapped the pump with a small hammer. To my relief and surprise the pump leapt into action and has not faulted since. The pump had sat idle for a number of years and just needed some encouragement to work. Total hours .3 of an hour, therefore, 18 minutes running yeaterday.