Replacement of indoor fan relay board of Trane unit and replacement of warranty condenser fan motor on Bosch unit. After replacement of Trane fan relay board found low voltage short on outdoor unit defrost board caused over amperage of low voltage controls taking out both the defrost board and the fan relay. Pulled R wire for outdoor unit for inside air handler so system can run in emergency heat mode. Will return Friday with defrost board for Trane system. Returned Friday 10/24 and replaced defrost board on system - cycled system to check operation - everything came on normally again. No additional recommended changes at this time.