Berlingo

[john.i]

Berlingo 51 reg speedo not working. New sensor fitted to driveshaft. Will work with ignition off, and then remove and refit black connector at rear of dash panel display board. Speedo flicks a bit like an electronic reset, then sits just off zero and will work when engine started. After switching off ignition speedo hits zero stop hard and stays there, next time no speedo working unless you pull plug and refit plug again before turning on ignition. Also found removing and refitting unknown fast acting fuse on centre of drivers side fuse panel does same as long as ignition and lights are off. Fuse now fitted with a pushbutton to press before starting car, until I can resolve problem. When battery went flat during investigation speedo would sit just off end stop and work. This stopped when battery charged. ANY SENSIBLE HELP PLEASE.