Thread: Trolling motor problem

This is from the repair manual

PART I - Case VI. AutoPilot function is erratic and doesn’t maintain a heading.
Step 1. Make sure motor is mounted within 5 degrees of level and there is no ferrous metal object(s) near the motor thatmay be affecting the compass (including screws and/or nuts).
Step 2. Check motor for excessive vibration. Inspect propeller and propeller shaft for damage. (Excessive vibrationcan cause the AutoPilot compass to oscillate causing erratic operation.)
Step 3. Check for proper voltage to motor while motor is under load. AutoPilot steering is susceptible to erraticoperation in low voltage situations. (Use of adequate wire gauge in boat or any leadwire extension is critical toavoid voltage drop / low voltage to the motor; as can an inadequate or corroded plug / plug receptacle.) AutoPilot Repair Manual 05/14/03 4- 3
Step 4. Check continuity of brown, yellow, blue, orange, and white wires in the coil cord with the coil cord stretchedout to length. If you find a break in continuity in any of these wires, the coil cord is defective. Replace coilcord, if required.
Step 5. Check AutoPilot compass control board for proper voltage levels at the optical sensor circuit. (See Minn KotaService Repair Bulletin #SB122099, AutoPilot Compass Control Board Trim Pot Adjustment Procedure – page4-6.)Step 6. Perform the Control Board / Compass Isolation Test following the procedure provided with the AutoPilot TestBoard – Minn Kota P/N 20 (see page 4-4). If operation is restored replace the sensor board compass assembly.If it isn’t restored, replace the main control board.

Trolling motor has been in same location for 5 years and worked fine and there is not any vibration so that helps with steps 1 and 2. I will check the other steps latter this week. Seams like you have a lot of experience and knowledge with boat repair.

THANKS

Wanafish