* Burnt-out points (if equipped): The points in a breaker-point ignition system are especially vulnerable to excessive voltage. Full battery voltage will cause them to burn up much faster, leading to ignition failure and possibly damage to the distributor. This is the most likely reason for bypassing the resistor on older vehicles.
* Shorter coil life: The ignition coil also receives higher voltage than intended, which increases the stress on its windings and insulation. This leads to premature coil failure.
* Increased radio interference: Higher voltage in the ignition system can generate more electrical noise, causing interference with the radio and other electronic components.
* Possible damage to the ignition switch: While less likely, the ignition switch might be subjected to excessive current, leading to premature wear or failure.
Why would someone bypass it?
The most common reason for bypassing the ballast resistor is a faulty resistor itself. If the resistor fails open (creating infinite resistance), the ignition system receives no voltage. Bypassing it provides a temporary fix, allowing the engine to run, but at the cost of the issues listed above. Another reason, though less common, might be a deliberate attempt to boost ignition energy for performance tuning (though this is generally done through other methods that are safer). However, this is not recommended on a 1973 vehicle and will likely lead to more harm than good.
In short, bypassing the ballast resistor is a band-aid solution that addresses a symptom (lack of ignition) but doesn't fix the underlying problem and risks damaging other components. The proper solution is to replace the ballast resistor with a new one of the correct specification.
