Corrosion on the up/down signal cables would be my first area to look at. I had similar problems on a B36/2002 where Bavaria had used ordinary copper wire, and the up/down signal cables had corroded throughout their entire length from the point where the portable controller plugged into the connection within the chain locker, all the way back to the solenoid located between the switchboard panel and the inside of the boat hull.
Removing and replacing that signal wire with tinned copper wire was difficult, but doable, and involved laying in a new three core cable all the way from the chain locker, through the forward cabin forward bulkhead against the hull, and all the way along the starboard side behind the half height lockers just under the deck. It worked a treat, but the secret was to use cable containing tinned copper wires to prevent further corrosion and having to do the job again some time later.
An alternative to replacing the thin signal wire cable was to go on to ebay, and buy a cheap (£10 at the time) radio operated winch controller for winches used on off road pick up trucks. They may be a little more money now, but many of the more modern radio operated controllers now come with two transmitters rather than just the single one I bought.
The receiver for the system wires directly into the solenoid controller, so no need to mess around behind all those cupboards. Also with two transmitters, it gives you some redundancy for the day you chuck one of them over side.
Having a radio control system allows you to operate the windlass from almost anywhere on deck, or even from a neighbours boat if it takes your fancy, so long as it is less than 50 feet away !!
You could also buy a radio control system from the windlass manufacturer, just be prepared to spend well over £100 instead of nearer £10, but it won’t do the job any better, and probably only has one controller included in the price.
