The answer to 'my tune-up keeps shutting off' is that there could be several common causes, such as a malfunctioning thermostat, a problem with the electrical connections, or issues with the HVAC unit itself. Symptoms may include the unit turning on and off repeatedly, inconsistent temperature, or strange noises.
Some potential solutions include checking the thermostat settings, inspecting the electrical connections, and cleaning or replacing air filters. However, if the problem persists, it's best to call in a professional HVAC technician to diagnose and repair the issue properly.