AM GENERAL issued a recall on the HUMMER model

On certain vehicles, the oil pressure switch which controls the power to the electrical pump can fail due to a missing rubber seal between the switch and the wiring harness. The missing seal allows contaminants to enter the switch causing it to fail in the open or closed position. If the switch fails in the closed position, the pump will continue to run when the engine is off, draining the battery. If the switch fails in the open position it will cause poor performance and possible stalling. Correction: Dealers will inspect vehicles for the presence of the seal. If the seal is missing, the switch will be replaced and a new seal will will be installed.