Tried to start car this morning. Dashboard lights were dim and a constant clicking noise & the engine wouldn't turn over. Battery voltage was 12V. Jump started with another car but did struggle to turn over. With engine running the ABS and brake light stayed on and if you operated the wipers or the indicators (in fact any other auxilliary equipment) the heater coil and the low fuel lights came on momentarily. The electric window motors were noisy. Incidentally, whilst running, the voltage at the battery went up to 13.5V. I think this means that the alternator is ok? Took the car for a short trip & it ran ok, however, the ABS and brake lights still stayed on & the fuel gauge went up and down whilst driving. When I parked (with the engine running) the speedometer registered up to 60mph & the mileometer moved forward. After turning the engine off, the engine would not turn over again. There was just a continuous clicking noise from the fusebox and the fuel pump when the key was in positions 2 and 3. Can anyone help? Many thanks in advance.
I would start with a new battery, quite often if they are not 100% you can get a car started, but the drain on the system from a dead cell in the battery will not give the ABS and other systems enough power to function.
Sounds like a bad earth -- Check battery connections / earth to body connection and also engine to body - usually an earth braid from gearbox bellhousing to body. Undo them and wire brush then WD40.