You need both fans, so replace that belt. It's a very cheap part and fairly easy to install. Also, I've heard one case of a thrown belt damaging the condenser.

The fan is variable speed, controlled with pulse-width modulation. The climate-control pushbutton unit N22 demands the fan if the refrigerant pressure or temperature or engine coolant temperature reach certain thresholds. There are multiple thresholds for each, and the fan runs at a higher speed as higher thresholds are reached.

N22 sends a signal to the pulse module N65 which actually supplies the power to the fan. At least this is likely to be the case on your '96. Other parts were used for this job over the years.