What could be the possible cause of low air compressor output?

The combination of choices 1 and 2 is correct because both excessive dirt in the intake air filter and a defective air compressor can significantly reduce the efficiency of the air compressor, leading to low output.

In the context of German traffic regulations, maintaining proper vehicle functionality is crucial for safety on the roads. A well-functioning air compressor is essential for the braking system in heavy vehicles, ensuring that brakes respond effectively when needed. Ignoring maintenance for components like the air intake filter or the compressor itself can lead to increased stopping distances and a higher risk of accidents.

Proper vehicle maintenance, including regular checks of air filters and compressor function, is outlined in various vehicle maintenance regulations in Germany. This ensures that vehicles operate safely and efficiently on the road.