hi i have a 86 z28 it was a tbi but it has a carb now and the wiring is extreamly bad!!! i have had only problems with the wiring.

first off when i shut the door and stick the key in i get power and it makes a buzzing noise but my head lights wont work and when i turn the key to start i loose all power. and still no head lights.

could this be a problem with the ignition swich
the other day i was geting out of the car and my foot got stuck on a wire that went under the kick pannel and under the center councle by the radio and thats when it stoped working i cannot find where this wire went to

 

Are your battery terminals tightened down? Are they crusted and nasty? I know that if your battery terminals are loose that when you turn the key you will lose all power and you wait a minute power comes back. But then again you said your wiring was a mess.