"If the connection between Circuits 614 (GY/O) and 623 (P/W) inside the safing sensor is broken, then the resistor on pin 12 is no longer in the diagnostic circuit explained above. Both resistors are needed to pull up the diagnostic voltage to the correct value. In this situation, the resistor on pin 11 is the only resistor inside the diagnostic monitor pulling up the voltage. Therefore, the voltage on pin 11 will be half of the normal expected voltage and the voltage on pin 12 will be approximately equal to the vehicle charging system voltage. The diagnostic monitor does not measure the voltage on pin 12, 50 the monitor bases its decision strictly on the voltage at pin 11. If the voltage at pin 11 is lower than it should be, the monitor will flash code 24."
Quoted from the diagnostic procedures, it sounds like what you are describing.