What does the trailer air supply gauge indicate?

The trailer air supply gauge is designed to show the amount of air pressure available in the trailer's air system. This measurement is crucial for the proper functioning of the trailer's air braking system, as it ensures that there is enough air pressure to engage the brakes effectively when needed. A good understanding of this gauge allows drivers to monitor the air system’s functionality, which directly influences safety and overall vehicle performance.

While the gauge's reading may indirectly relate to other systems in the trailer, such as the suspension and braking, its primary role is to indicate the air pressure rather than the condition of those systems or aspects like cargo level. Therefore, recognizing the gauge's specific purpose in measuring air supply is essential for safe and effective vehicle operation.