I posted this originally in the 1st gen section but I didn't get a single response. The previous owner of my 68 shredded the wiring harness. The wiring diagram that I have does not indicate polarity on the coil. The new wiring harness that I bought has a blue wire for one side of the coil and for the other side two wires joined at the connector one white with brown dashes and the other is yellow. The polarity on the coil is marked, I just need to know which side to connect each wire to. I don't want to ruin my coil or my distributor by guessing.

 

Do you have a test meter? With a conventional points distributor with a separate coil, the coil power is a resistance wire, and should have around 10 volts coming out of it. The wire from the distributor goes to the - on the coil. The original coil supply wire was a white with orange/purple stripe. The yellow wire comes from the starter solenoid to give the ignition a full 12 volts only while cranking the engine over. Those two wires go to the + on the coil. The other wire that's left should be a provision wire for a tach, connecting to the - on the coil. Now, what type of ignition are you running? If you changed over to an HEI distributor, you need to run a new clean wire with a full 12 volts going to the distributor.

 

That's the info that I needed. Thanks.