No, the AC fan's failure in a 1995 Chevy Monte Carlo Z34 would not directly affect the temperature gauge or cause heating problems. The AC fan is only for cooling the *interior* of the car. The engine's cooling system, which affects the temperature gauge and heating, is completely separate. The engine cooling system uses a radiator, coolant, thermostat, and a different fan (often called the radiator fan) to regulate engine temperature.
If your heater isn't working, the problem lies elsewhere within the heating system itself (e.g., thermostat, heater core, blend door, coolant level, etc.), not the AC fan. A malfunctioning temperature gauge, likewise, is typically due to a sensor or gauge issue, not the AC fan.
