My peugeot 206 2001 wont start when ignition switch is turned on ?

-when we turn key dash lights up rev counter goes haywire, starter motor checked and battery checked ?If you have removed the starter and the battery and they are working ok, then next to be checked is the switched feed from the ignition switch to the small wire on the starter motor as that's where the power comes from to energise the solenoid,hope this helps