To test a 24V transformer with a multimeter, first ensure safety by disconnecting the transformer from any power source. Set your multimeter to the AC voltage setting for testing the secondary side of the transformer. Connect the multimeter probes to the output terminals of the transformer. If the transformer is functioning correctly and powered, you should read approximately 24 volts AC on the multimeter display. If you’re checking continuity on the primary side with the transformer off, switch your multimeter to the resistance setting, and measure across the primary terminals; a low resistance value indicates good continuity. Additionally, checking for any shorts between the windings using the resistance mode is advisable. If you’re looking for degradation or issues over time, consider using an insulation tester or dielectric absorption ratio device. This relates back to how to test furnace transformer as well, ensuring proper functioning and safety in industrial applications. Always interpret the results based on the specifications provided by the manufacturer for accurate analysis.