Need help guys. 66 cutlass 330 engine. Here's what I got. Headlights work, no taillights/brake lights/reverse lights. When I turn the key dash lights come on. When I move to start... nothing. No Click...nothin. The battery is new. power at the relay. Testing large nut side at starter no power. Key on. No power at solenoid when key moved to start. Moved to a neutral safety switch. Removed the two purple wires from the safety switch. Tested both wires. No power. No difference in voltage moving to start position.

For clarity. The starter should always have power correct? In addition, the two purple safety switch wires, constant power? Terminals and wires are all clean. Any guidance would be appreciated.

 

You should have constant power to the large terminal at the starter coming from the horn relay power stud. You should have power to the purple wire from the ignition switch to the NSS only when the key is in the start position and then power to the S terminal at the starter if your in park or neutral. The tail light, brake light, and reverse lights are a separate issue. There are no fuses or fusible links in the start circuit.

 

Thank you for that Clarity. I have no power at starter and no power in any capacity to the safety switch. There is power at the relay and coil. Any guidance for the next steps would be very much appreciated.

 

If you have power at the horn relay stud then the terminals are corroded or making a bad connection for some reason. That stud is where power is distributed to the rest of the car. Note a volt meter will read voltage with the littlest connection but the connection will fail under load.

 

When you turn the power to start do all the dash lights dim like a large power load is going out, or do they remain bright?

 

Get a test light. Start at the battery and trace the circuit until you find where the power stops. There's no magic here, just thorough troubleshooting.
Also keep in mind that the circuit needs the ground cable to be clean and tight in addition to the power cable.

 

@Koda The lights on the dash dim.

 

@joe_padavano Thank you, Joe. I've been using my Voltmeter. I tested all the fuses. Here's what I got. Power at the terminal. That goes to the relay. The nut and bolt on the relay read 0. But the cables read 12. So Terminal to relay good. No power at stud. Cable from relay good cable touching starter no power. I have no power at the neutral safety switch, under the center console. No power underhood for neutral safety switch junction going to the starter.

 

If the lights dim, the load is there. I think your battery is weak.

 

Sorry, but that isn't physically possible. If there's power on the wire, there's power on the stud and nut. If you can't get a reading on the voltmeter, you've got a problem with corrosion, in all likelihood. I would strongly suggest that you disassemble every connection, thoroughly clean, and reassemble tightly. Also, disassemble and clean the battery terminals. Check the connection of the negative battery cable to the block.

 

Update. Bad neutral safety switch. Bad starter. Corroded ground, and power. Installing a new starter tonight.