Minn Kota Ulterra – lower unit issue?

I have a 36V Ulterra setup, and I have an issue where when I push my remote button to start the prop, it won’t spin. If I give it a quick spin with my hand, almost like jump-starting an airplane prop, it kicks on and holds power, but it doesn’t seem to be consistent power and it will eventually cut out and stop running. I can also hear friction within the lower unit, like the armature is making contact a bit. Has anyone ever seen this? It’s almost like when a capacitor on an AC unit goes bad, and it won’t spin the fan blade when the unit kicks on, unless you manually spin it to get it going.

The batteries are quite a few years old, but charge well and I show a full 36V to the trolling motor. Could the batteries be old and even though it shows 36V, it’s not providing good power when I put a draw on the system? Or is it likely the lower unit needs some work?

bbuchho90 wrote:

If I give it a quick spin with my hand, almost like jump-starting an airplane prop, it kicks on and holds power, but it doesn’t seem to be consistent power and it will eventually cut out and stop running. I can also hear friction within the lower unit, like the armature is making contact a bit.

Sounds like moisture intrusion. Causing all kinds of issues. Brushes not free to move under spring tension, thus not making good contact with the armature. Armature dirty where brushes should have been making good contact. Build up of rust on the body of the armature (friction and contact mentioned)
Sounds like a full motor rebuild is needed.

What Dave said.
Same thing happened to mine. The direction would work but prop would not. Took it to our authorize Minn kota center and all it was one wire from one of the brushes had come off. Scott said he had never seen this happen. He reattached it and put in new bearings and seals. Now it’s just like new.

Are you near a service center or even Mankato MN?