Drum seemed to be locked. -Waltsailor wrote...
When it's locked. (MAKING SURE YOU DON'T HAVE THE CIRCUIT or SWITCHES ACTIVATED -- lest you end-up hurting yourself, or someone...) Take the winch or windlass handle and see if it is jammed "down" as well as "up".
If it's really jammed, then you'll have to pull it apart; and, see if you have the drive/gears messed-up, or the motor.
Then try to energize down, then up (TAKE THE winch handle OUT before you try that, or else).
If it's jammed, it's not the solenoid.
if it's really jammed\ ...My suspicion is that it's not the feeder wire or the solenoid, (Those items might have issues, but I believe, your current issue is a not that).
If it's not locked, and just "stopped", then it should reverse down, shouldn't feel like you have a blockage or jamming. In that case, it might be the motor windings, brushes, or maybe the solenoid/switches.
IF IT'S JAMMED, you really should get a spike in the current draw, the breaker should pop -- but you may have an oversized fuse. be careful, but you should see a lot of load draw. IF you weren't running the engine, you might not have enough "umph" in your battery, but I you'll show some load.