Motor guide great white 36 volt power loss

I have a 22ft bay boat with a 36 volt motor guide "great white" trolling motor that has a significant loss of power. It seems to run about half power, barely moving the boat. The unit does not have a plug and is directly wired through a big foot. The big foot is starting to go out and I am going to replace it. Any trouble shooting tips before I start would be appriciated

Silvertip

Supreme Mariner
Joined Sep 22, 2003 Messages 28,770

Re: Motor guide great white 36 volt power loss

You said the Big Foot is "starting" to go out. It either works or it doesn't. With the boat in the water, measure the voltage AFTER the Big Foot with the motor set at high speed. If it is 36 volts the motor is going south or the wiring between the Big Foot and the motor is bad. If the voltage drops below 36 volts AFTER the Big Foot then there is a problem with the Big Foot or the wiring between the batteries and the Big Foot. OR, one or more of the three batteries it takes for 36 volts is going bad. Have them load tested. Just because they measure 36 volts with no load does not mean they are good.