instrument cluster fails when rpm exceeds 1900

[gavincollison]

So Having a bit of bad luck with the wife's car. I'll give you the past few months history just incase it's relevant.
Car has been sat on the drive for a couple of months. replaced lhs wishbone, rear exhaust box. Battery flattened due to non movement so charged overnight and seems to be fine now.

Yesterday she phone's me up and says that all her dials went to zero and brakes, abs and airbag fault came up.
Now all we are getting today is Loss of power to Instrument panels but only above 1900rpm. comes back on intermittantly at 4-5k. I've had the instrument panel cover off and the cover under the steering wheel. Jiggled the leads around at idle and seems fine. As soon as engine reaches 1900rpm. Power gone. Theese seem to be only symptoms.
Only cheap resoloution I can think of is new battery.
Any ideas please


Thanks in advance

Gav