Ran into interesting problem. Just replaced all wiring, gauges and switches. Upon completion of installing gauge cluster the fuel and ammeter does not function even though the fuel gauge was bench tested. When trying to rollout the headlights they get no current and both direction indicator lights on cluster come on with switch pushed in either direction. I’m scratching my head trying to figure what I hooked up wrong. In case it helps it’s a 1964 coupe

 

Welcome to the Corvette Forum. Sounds like a lot of things have been worked on, any chance one of the connectors is not making good contact, like the banana shaped connectors from the steering column or maybe the twin harness plugs on the engine compartment side of the fuse block? And, any grounds not fully connected like the single Black wire that connects to the spade connector at the top of the instrument cluster?
Mike T - Prescott AZ

 

The headlight roll over switch is not connected in any way to the turn signal indicators. It doesn't even use a ground inside the car. The battery gauge has a b/w wire connected to the red wires at the horn relay and a black wire connected to the red wire at the starter solenoid. No ground, and should work key on or key off. You need to carefully check your wiring at the starter solenoid. There are two black wires with ring terminals there. One comes from the case of the heater fan and grounds the fan and wipers. The other goes under the starter mounting bolt on the block. If you switched those two black wires you will get all sorts of electrical anomalies that are otherwise unexplainable. Look and report back if you have the ground wire at the starter mounting bolt correctly connected. It's the larger of the two ring terminals.
The head light rollover switch comes from the circuit breaker mounted on the drivers side kick panel and goes to the switch and then the voltage out of the switch goes through the outboard connector on the firewall plugs, as do the front turn signals. The overall symptoms suggest that you have voltage getting places it shouldn't and that you may have more than one issue. Measure for 12v on the red center wire going to the headlight rollover switch. It should be 12v all the time, key off or key on. Then when you pull the switch up, the voltage is present on the yellow wire AND the red wire. When you push the switch down, the voltage should be on the red AND the green wire on the switch.
If you'll check those two things and post back, I think we can narrow down the issue(s). (Ground wiring at the starter and power wire at the rollover switch)