Zero Turn Mowers

Have a Z5426 which had a safety interlock issue. One lever switch was cracked it looked like the obvious fix. I replaced it but engine would still stall when disengaging either lever or parking brake. I taped both lever switches down and had to disconnect the brake linkage so I can run with the brake lever up but have the actual brake disconnected in order to cut my grass. With all three switches in the "safety postion", I can get my machine to run as it should but would prefer to fix the actual problem. The seat switch still appears to function since when running with blades going, the motor turns off when lifting off the seat...

My question is are there any other switches involved besides the four I mention above (two lever, one brake, one seat) to check? I was planning on replacing the brake switch but don't know what to do next if that fails...any opinions? DIY is preferred due to a tight budget. Thanks!