I dont remember in 99 if Basscat used the 4 wire system for the plug, or had gone to 2 wires. If youll pull the trolling motor receptacle, youll probably find the other end of the wire.JohnBTW, when running a 3 battery, 36V system, you need to make sure the cranking battery ground and the trolling motor ground are connected to the same battery, and that battery is the one used for cranking and accessories else you will invite electrolysis. JohnJones Trolling Motor Services870 773 3474Motorguide/MinnKota/PowerPole/Lowrance/Humminbird