Connect Pin 4 directly to GND.

Before running an LTspice simulation, it is essential to understand the internal building blocks of the Texas Instruments TL494 . The IC incorporates all functions required for standard PWM control circuits:

Selects between single-ended mode (parallel output) and push-pull mode (alternating outputs). Importing a TL494 Model into LTspice

Pin 13 dictates whether the dual output transistors operate in parallel or push-pull mode: