Where is the fuse located in a Trane air handler?

The low-voltage control circuit fuse in a Trane residential air handler or gas furnace is located directly on the integrated electronic control board inside the main blower compartment. To locate and access this fuse safely, you must first turn off the electrical power to the air handler at your home's main circuit breaker panel, then remove the front service access panel or door of the indoor unit. Once the compartment is open, look at the main electronic control board where the low-voltage thermostat wires connect; you will find a small, automotive-style blade fuse—typically rated at 3 amps or 5 amps—plugged directly into the board surface. You can verify the fuse's condition by pulling it out to inspect the internal wire. You can verify that a replacement fuse is working when powering the system back on restores thermostat display power.