Is power always on at fuse box? It seems I only have power to half of the fuse box in my 1975 corvette

buy the old old , manuals used?
back then 25 years before digital books from GM existed,. 2000 up is digital or pdf ./
we buy the real books used now, from ebay
or googling to find them and are rare.

did you check the light switch? or a broken wire

The headlight switch contains a circuit breaker for the headlights. You would need to know if you have power in and out of the headlight switch for the headlight circuit. You may need a new switch.

Your dash light...(instrument panel fuse is blown) or the headlight switch is bad...If you need any parts...the internet for corvettes is awesome. Hope this helps...(Just over 100,000 ) corvettes were made in 1975...

LIGHT SWITCH 15 AMP FUSE CIRCUIT BREAKER / TAIL , DOME , COURTESY 10 AMP FUSE / MANUAL RADIO 4 AMP FUSE / AUTOMATIC RADIO 7.5 AMP FUSE / HEATER 10 AMP FUSE / AIR-CONDITIONER 20 AMP FUSE / BACK UP AND BRAKE ON 10 AMP FUSE / POWER ANTENNA 15 AMP FUSE. THE ELECTRICAL BOOK DIDNT HAVE A DIAGRAM BUT IT TOLD WHAT AMP EACH COMPONENT USES AND VOLTS FROM GENERATOR. IF YOU HAVE A 55 CORVETTE YOU HAVE 6 VOLT ELECTRICAL SYSTEM.IF THIS DONT HELP YOU CAN GO ON LINE AND BUY A 59 CORVETTE REPAIR MANUAL.

check ur relays under the hood

There is not always power onevery fuse in the fuse box. These days you may find that a circuit is fused on the load side of a circuit such as your headlamps. The fuse for components such as this will have the power coming from the switch, through the fuse and out to the component. In c case such as this the fuse will not be powered until the switch is turned to the on position.

hmm..there might be a fuse box under the hood or most likely in the dash or under the passenger or the drivers dash..hope i solved your problem :)

Go to one of the major Corvette club of America web sites , register and ask. Someone is bound to have this.