Upon arrival inspected furnace and found unit code 24 with blown 24v fuse. Installed test resettable fuse and test run system, no errors until ac unit cycles, inspected outdoor unit and found shorted 24v 1 pole contactor. Coil for part was burnt and reading 0.8ohms. Replaced with 1 pole contactor and test run system. After repairs unit came on cooling with no issues, I do not have a spare 3a fuse on my truck so lil popper will act as permanent fuse until we return for heating maintenance.