Sorry if i miss led you, i meant if the earth cut out wire from the ignition unit to the kill switch was trapped and earthing out the ignition ( this is all the switch does, takes the wire to earth which cuts out the ignition ) are you sure the new switch is working properly? do a basic continuity test on the switch, if it has two terminals in the off position you will have continuity, in the on position you should have no continuity, if it has one terminal check between the one terminal and the metal body of the switch.
Husqvarna man, January 2010