Small Engine Troubleshooting Problems? Ask a Mechanic Now.
Husquavarna model of mower? Do you have a voltmeter to check for voltage a the pto switch? You replaced the switch? did you examine the switch plug for getting hot? plug may not be making contact with switch terminals. Will the pto clutch engage the magnet if you run wires direct from battery to the clutch to be sure it is good?
Model number? Which switch, the pto switch? The two wires to the pto clutch good? Have you tried two new wires from switch to pto? No relay between switch and pto?