my 60 road runner has the ignition coil with radio condensor .What is the purpose of the resistor? mine is shorted out it runs when unhooked but not when its hooked up is it needed

For radio interference.

A condensor is not a resistor, it is a capacitor. When you put your meter on a capacitor to measure it's "resistance" you are charging the capacitor. You need a meter that reads capacitance, not an ohmmeter, to see if it's good or bad.

See section 5.2.1 for what you should see when trying to ohm out a capacitor.

https://www.apogeeweb.net/electron/how-to-test-a-capacitor.html

The coil, generator, alternator could generate a pulse noise interference heard through an AM radio. The condenser(capacitor) acts as a shunt to null out the interference. Just like the condenser within the dash for the gauge voltage limiter, or inside points distributor to absorb the spark to minimize damage to the point's contacts.. Note that an AM radio had no built noise suppression, since back then AM radio was the main entertainment...


Just my $0.02...

It is not needed to run the car. If it is shorting out it is grounding out the coil.

If you are concerned about stock appearing, just leave the condenser mounted but ditch the wire under the coil in the bracket. That’s what I do on all, unless you are really interested in listening to am radio as you drive around!