this is an oem Blue Sea 7003 circuit breaker 100 amp panel mount, with 2 studs on the back for the wire in and wire out. (vintage 2005.) there are 2 identical 7003's, one 100 amp controls the windlass , and an exact duplicate 100 amp CB controls the 'main fuses' for 12 v. we were sitting at anchor having dark n stormys. or a while we'd had no windlass there was no power coming out of CB for windlass into the control box, the reset leg wouldn't go up, so i bought a new switch. friend said, i'll replace your windlass circuit breaker! i said nah let it go. he siad, let me. there's ' a main 12v rotary switch shut off, we shut it off. he went in to the panel and tried to get the old CB out, he'd hve to take the hole panel off so said nah let's do it later. turned main 12v rotary switch back on -- i now suddenly have no 12v dc circuits whatsoever on the boat: no nav lights, no engine panel, (can't start engine) no VHF, no refrig., no cold beer. the 100a main fuse circuit breaker --which he WASN'T working on -- won't reset, the little leg won't go back. up..pressed the red button repeatedly , the little leg won't go back up. note the only thing running when all this happened was the refrig. Any ideas??