My trusty cat 246b has run fine for years, parked it w/o incident Fri nite but in morning no juice. key turn is dead. battery voltage good, cleaned terminals just be sure. no lights, no start. wondering about relays or fuse, but my book says fuseblock on wall behind seat (nothing on wall). there are several relays and a circuit breaker in engine compartment, but i have no elec schematic to know what to check. Any ideas?