An overhead door immobilizer deactivates power to the power head operator in a conventional overhead door system to prevent the door from damaging the hatch portion of a vehicle when the hatch portion is in an open position or orientation. A hatch position transmitter (HPT) module mounted on the hatch portion transmits a coded RF signal. A power receiver module (PRM) receives and decodes the HPT RF signal and operates to deactivate power when the hatch position is in an open position and activate power when the hatch position is in a closed position.