Still no crank after cleaning starter bolts and starter body/engine block. Sanded and cleaned all harness terminal connections. Swapped interlock switches, cleaned ground wire connections from Deadman switch. But will crank if I ground separately from negative post to mower frame. I guess I could just call it a day and run a separate ground wire from the negative post to the frame?
Mowers are made down to a price
As such the battery straps are the thinnest that will do the job and simply crimped at both ends.
These wires are prone to moisture wicking down the the wire and corroding them through in the middle
If you have cleaned both ends and made a clean good contact to the battery & body but the mower still won't crank. but it does when you jump the ground then your ground strap is deceased , dead,kaput, no more of this earth, broken, unfit for service & requires replacement.
By a long way the JD naked ground wires are the best to use
Next best is the naked platted straps which you should be able to get from any good auto supplier
But if you want confirmation take to the insulation with a knife and peel it back.
Not uncommon to find them totally corroded through is several places
