Hi Bob, I'm not an expert on the electrical configuration of every year of the big Healey but I have been reading about these things for about 15 years. My Bj7 is highly modified in that i have installed two fuse boxes. If your car is original you probably will find that you only have two fuses. Both on the firewall just above and to the right of the throttle linkage on a LHD car. An exception that is common is that many people have installed an inline fuse on the wire off of the light switch that feeds the rear running lights. As for getting along in an emergency without fuses you can note that your headlights are non-fused (as has been general practice on many cars from the '50s & '60s, 1950 era Chevrolets had a current overload bimetal strip built into the head light switch to provide some protection incase the headlights faulted.) Also your ignition power to the coil and starter is non-fused so you would always have ignition unless of course component failure. So you would probably be able to get along if you blew one of the two fuses that you do have. Of the two fuses that you do have, the top one is energized when the key is turned on, it supplies items such as, wipers, heater, gages, I think the flasher, and brake lites and overdrive. It is a 35 amp fuse. The bottom one is a 50amp fuse and it is hot all the time and supplies the Horns. ....! go figure. It is also intended for period expected auxiliar equipment such as radio and fog lights. Dave.