What could prevent a Thermo King unit from starting?

A Thermo King unit may experience startup issues due to several reasons, and among those, dead batteries, faulty wiring, or control module problems are significant contributors. If the battery is dead, it will not provide the necessary voltage to start the unit. Wiring issues, such as damaged or corroded connections, can disrupt the electrical flow and prevent the unit from engaging properly. Similarly, faults in the control module, which is responsible for processing signals and commands within the unit, can prevent it from starting if it is unable to function correctly.

While other factors can influence the operation of a Thermo King unit, they tend to affect its performance rather than its ability to start. Blocked airflow can exacerbate cooling issues after the unit has started but does not typically prevent startup itself. Faulty refrigerant levels can render the unit inoperable under certain conditions, but they would not stop the initial attempt to start. Excessive heat levels might lead to shutdowns or operational failures during use, rather than preventing the startup altogether. Thus, the combination of electrical failures represented by dead batteries, faulty wiring, and issues with the control module stands out as the primary reasons a Thermo King unit may not start.