My 1977 fiat has all the lights and horn
working, the battery is charged but the key
in will not make a single noise. My starter
is brand new but when I turn the key it
does nothing except turn on the electric
items. What's the issue
Should check to see if there is power running down to the small wire connection on the starter solenoid when someone is turning the key to the start position. If there is no power then either the starter relay, ignition switch, clutch safety switch would need to be checked.
It never hurts to clean the battery cable connections and insure that they are tight.