How often do you wash your mower? Disconnect your negative ground cable from battery & charge battery with 10amps overnight. If your battery has caps, remove & check acid level in cells, if low fill with distilled water before charging. Wear Safety Glasses! Use eyes & hands, you have a loose ground wire or a hot wire touching ground. Check PTO clutch connection then check air gap at three windows in clutch, gap should be .010. Whenever replacing electrical components on your machine, always remove ground cable from battery first & place out of way of battery negative post, cover negative post with shop rag, use a jumper wire with alligator clips & connect to positive post on battery & negative cable that has been removed from battery for 2 to 3 minutes. This will allow computer module, relays, etc. time to reset themselves. Harbor Freight has jumper wires with alligator clips. Perform this task last after completing electrical work. The same remedy can be performed on an automobile with "CHECK ENGINE" light staying on. Several months ago my nephews family came to visit & started talking about his wifes vehicle "CHECK ENGINE" light staying on for two years or more. I asked my nephew if work had been done on vehicle recently & which shop performed repairs replacing electrical components. My youngest son grabbed a jumper wire & performed above procedure, nephew installed key in ignition started vehicles engine & looked at instrument cluster then turned to my son & I saying, that's the first time in two or more years light did not come on.
Thanks, Mark