When I went to air up after my last trail ride, my PowerPlant compressor didn't work. To see if I had a general failure, I tried to power the winch out and in with the same "dead" result. Got home, called Warn, got the service manual emailed to me and worked with a great tech named Mike.
I did some troubleshooting with Mike, and decided I needed to send in the winch for repairs since I had power to the female connector for the hand control, we determined that the 10a fuse was good, but nothing worked and it seemed like a part called the "connector" was likely the culprit. BTW, I did put a meter on the hand controller to verify that all switches were actually working.
On my JK with Metalcloak frame built bumper, ya gotta disassemble the bumper to get to the winch mounting bolts. Makes it a real PIA for would-be winch thieves, but a real PIA when you have a failure too. With this bumper, the winch sits between the frame rails, and you only have about 1/4" between the back of the winch and the grill.
So out comes the winch, but something looks fishy with the 10a fuse holder that controls everything on the back of the winch. I could see some what looked like white power and thought to myself "why is there white power on the fuse holder". Well when I opened the fuse holder, it looked like a highly corroded battery terminal. I pulled the fuse and it fell apart.
So my winch failure was caused by electrical corrosion inside the fuse holder. The corrosion allowed enough voltage and current to pass through the fuse to give a solid 12v reading on a meter, but when a load was applied, it provided a high resistance open.
So I'm going to extend the 10a fuse leads so I can get to the dang thing in the future without pulling the winch. I'll also fill the fuse cavity with dielectric grease.
I did call Mike at Warn after I discovered this issue, and he mentioned that he has seen a few cases of this happening, especially in areas where magnesium chloride is used for winter road ice melting.
Just my latest experience. On the bright side, I will install some grill guards since I have room to pull the grill now.