My thoughts are I'm not sure I understand what you're asking. By cable caps, do you mean the spark plug caps? They shouldn't be tested through for a coil test because they are resistor spark plug caps. Your reading won't match the given spec because of the added resistance. You do test spark plug caps but by themselves, to see if their resistance value is correct. These old original spark plug caps can and do go bad. That is usually indicated by a much higher resistance value than the spec.