Grasshopper 430D dies with when lights turned on

[jrv97240]

New to me Grasshopper 430D. Was mowing with it the first night and went to turn the lights on and it immediately killed the engine. Turned the switch back off and started back up and mowed fine rest of the night. I recreated the issue several times in the garage afterwards, it does it every time the light switch is engaged. Any ideas?