kill switch

I have a Grasshopper 226V zero turn from around 2011 with 535 hours on it. It has a B&S 724cc, 26HP twin cylinder engine model 44P977-0110-G5. I recently removed the motor and replaced the seals and gaskets (was leaking from the sump). While I had the motor off, I cleaned the flywheel and...

BR800 blower, runs perfectly but can not shut off with kill switch. I used ohm meter to verify both the yellow and black wires in the handle have continuity. I also cleaned the contact point on the kill wire inside the handle. I suspected bad ground b/c before cleaning the contact point there...