Upon arrival customer stated that heat was not working properly. Stated that outdoor fan would come on and then shut off. After inspection of two year old system found that unit had a bad pressure switch at outdoor unit and defrost board. Sent call for heat from thermostat and everything turned on at indoor unit. Checked outdoor unit and saw unit would come on for a minute and then shut off. Tested outdoor system and removed pressure switch from board and bypassed it. When I did this system would run and not turn off. When pressure switch was added back into the equation it would then trip outdoor unit causing it to stop working. Advised customer of issues with system. Gave customer estimate for repairs on system, customer did not choose to move forward at this time. System is not working properly.