Any idea what the issue is with the troll motor on my boat?
Been There, Done That.
Is the battery power up to the required level? That's all I can think of without tearing it apart.
Debris around the spindle .
Suggest you take it to someone who knows what they're doing. Most likely is a poor connection somewhere due to water getting in & without being rude I suspect diagnosis & repair is probably beyond you or you'd have already done it.
As a guess, electrical contacts. If you could put another pedal on it, you split the system in half. I don't have any experience with these. Maybe water has infiltrated the thing.I would have already had it apart.
WD40 will stop it sticking.