Hi. My TD5 has been stood for several months whilst I’ve been doing work on it, new cills, windscreen, gaiters and brakes ready for MOT. I came to start it up and the battery was flat so I charged it up and tried again. Now getting a fast clicking noise and dash lights flicker on and off with clicking noise. Tested battery and it’s got 11.9 volts. I tried another battery off a 2.5 diesel transit (12.6 volts) and the same thing happens, fast tapping noise and dash lights flickering. Could this be an earth fault.