I'm rebuilding one of my coils that was marked "good" when I stored it originally, that is, it ran and produced a good spark. I tested between the two front terminals and got a reading of 3200 ohms, so I carefully removed the tar and the old capacitor. Now I have no reading between those terminals at all.
Does the capacitor have to be in the circuit, or did I get a little too "dig happy" with the screwdriver and damage the secondary winding somehow?
"Dig Happy" ???? May have damaged th3e secondary winding...
Are the wires securely soldered to the terminals ??
One or two of the coils I have had for rebuilding have suffered an open circuit secondary, where the owner had previously removed the condenser and damaged the winding. Fortunately, such damage is usually on the outside of the winding, and the secondary can be unwound back to the continuous part of the winding. Given the high turns ratio, the loss of a hundred turns or so doesn't affect coil operation.
Another common cause of open circuit readings is where the coil windings are soldered to the terminals on the wooden box. Sometimes there's still some enamel on the wire where there should obviously not be.
So, it sounds like in order to find/fix the problem I'll have to dig the rest of the tar out. Arrgghh!
With a abundant supply of original Ford coils, get yourself another to rebuild and take precautions not to make the same mistake.
Hundreds of turns of fine wire encased in old tar, and you expect to fix ??? You're a better T man than I my friend.
Most don't do this but I always loosen the tar from the wood case on the side the capacitor is on by sliding a putty knife down between the tar and the wood. That side, once loose, can be removed/pried off the case which leaves a clear shot at the capacitor. The glass insulator is left in place making winding damage darn near impossible. A few drops of wood glue on the "teeth" holds it place when closing the case.