Which of the following is considered an appliance major repair?

The selection of overhaul of a hydraulic pressure pump as the correct answer is rooted in the complexity and significance of the repair involved. An appliance major repair typically refers to a task that requires substantial effort, specific technical skills, and often involves disassembly of the appliance. Overhauling a hydraulic pressure pump includes a thorough inspection and repair of internal parts, which is a detailed and intensive process, indicating a major intervention in the operation of the appliance.

In contrast, the other options involve lighter repairs or maintenance tasks that do not have the same level of complexity. For instance, replacing an electronic component may involve simply swapping out a part without significant disassembly of the main systems. Changing oil filters, while important for maintenance, is generally straightforward and does not delve into the core mechanics of the appliance. Similarly, repairing minor wiring issues usually entails simple fixes that can be completed without a comprehensive understanding of the overall appliance mechanics.

Thus, because the overhaul of a hydraulic pressure pump involves significant mechanical work and expertise, it is classified as a major repair compared to the other choices that represent simpler maintenance activities.