Cadillac Repair: 1973 Cadillac Eldorado electical question, power trunk release, cadillac eldorado

Question
I have a '73 Eldorado convert.  Took the car for a season end drive today.  When I left home all seemed well with the electrical.  Somewhere along the way, I noticed that the interior lamps quit working.  Upon further investigation I noted more electrical things not working - all fuses appear to be good but I can't seem to detect any power at the fuse box.  Headlamps work - but no marker lights or brake lights.  I also noticed that horn is not operational now - as well as no power door locks - no power trunk release - no radio - etc.  However, the turnsignals, headlamps, and power windows all still seem to work fine.  Do you know if there is master fuse or master breaker for the main power source leading to the the fuse box?  If so, where would I be able to locate it?  This strange problem is really stumping me.

Answer
Take a look at the starter where the battery cable is connected and you will see several RUBBER COVERED wires vs the standard PLASTIC COVERED wires. These RUBBER COVERED wires are called FUSIBLE LINKS and are made internally of aluminum wire so if a short circuit appears these fusible links MELT internally. Check for battery voltage at the fusible link where it is connected to the PLASTIC coated wiring about 4"'s up in the wiring harness. If no voltage passes thru the fusible link, You can first try replacing it as you can buy it at any auto parts store.