Same exact thing happened to my Maxxum 80 a couple of years ago. The little on/off button under the foot control was bad. I bought one from a trolling motor repair shop in Houston and swapped it out myself. Simple fix.
I'm looking at the part list for my Maxxum. I believe the part number is 2260810 (clip, reed switch). I remember the cost of the part being around $7 to $10.
Edited by GeeDub (10/01/16 07:35 PM)
Edit Reason: Added part number