Well it was either the unit itself which was defective or doing some detective work & finding out why it kept powering down & it sprung to my mind last night whilst the the new unit was in the car that I should try the lead via the Gps mount & all appears to be ok. Before when the unit was mounted on the old spare Gps mount the blue charge light would just ‘flicker’ where as on the new mount there is a solid blue charging led. Didn’t reliase aswell they there is a 312G out aswell now but can only seem to find these on eBay??