[george kujanski]

John, taking the wire off the coil and measuring voltage will measure battery voltage. The coil and resistance wire must be connected WITH THE POINTS CLOSED to form a complete circuit, which then forms a voltage divider giving you ideally about 8 volts (give or take; it won't be battery voltage).

I believe on a '68, similar to my '67, there should be two wires to the (+) side of the coil. One wire is plain, and is used to provide battery voltage to the coil for better starting, The second wire is the resistance wire, and active in the RUN position; the first wire is dead in the run position. This feeds slightly less voltage (the 8 or 9 volts above) to the coil which makes the points last longer.

Now if you only have one wire, and it is not a resistance wire, that is not correct. Use your multimeter, if it has a volts scale to measure the coil (+) voltage with the key in the RUN position and the points closed. You may have to bump the engine over a bit to insure the points are closed, or, alternately, use a jumper to ground the (-) side of the coil to make sure. Do not maintain this connection too long, as the coil is drawing current constantly. Also, when you disconnect the jumper wire, the coil will fire, so watch out for high voltage; keep away from the high voltage terminal. A reading of 8 or 9 volts (less than 12.6 in any case) indicates you have a proper resistance wire in the circuit. Measure with the positive meter lead to the (+) terminal and the negative to engine block.

If all above is OK, I can't explain why the coils are going bad, if indeed they are. More likely, the problem is elsewhere as John says, and you should look elsewhere if your resistances are ok.

The grounds shoould be braided bare wires bolted from the rear of the block to the firewall sheet metal somewhere.

Regards, Georg