The above is part of my project design. 'BRAKE_CTL_3' is output pin from uController. It sends 0 or 1 to drive Q4 to turn it on or off. 'BRAKE_LSD_3' connect to one end of Relay. Other end of relay is connected to +12V. I would expect my design to turn relay on or off. However, relay is always turned on(closed). When I measured the pin output at 'BRAKE_LSD_3', the voltage switch from 0 to 3.3V instead of 0V to 12V(ideally). I dont know whats wrong with my design? Can anyone help?