Buzzing from dash when turning on ignition

[Crazytransit]

Hi
I'm hoping someone can help.. ford transit mk7 56 plate, 2.4td. When I turn on ignition a get a loud buzzing from dash, counter shows all numbers as 8's, rev counter shoots up to 1000 revs. since this first happened other week I no longer have central locking, interior lights, cigarette lighter. This buzzing is now everytime I go to start it, and since the first time It takes many times to start. I've checked fuses and can't find any blown. Does any 1 have any ideas. Thanks

[knobby1]

Front battery is possibly knackered. Very common.

Also check all earths.

Lord Knobrot