Help

Hey guys I have a 2010 tacoma. I'm having some problems first I thought my headlights were blowing out. Turns out they just go out and when I take my head assembly apart and plug my bulb back in my connector and tap on it they come back on I've replaced multiple bulbs thinking they kept blowing and they still keep going out. I took it to the dealer they couldn't find anything wrong. Next my blower works on all speeds if I screw with the switch sometimes that itself doesn't work. I blew a bulb in my fan speed control dial too. Can all these electrical problems be related? And also I'm not sure if my blower motor is going bad but my defrost only blows out the drivers side vent. Can someone please help me. Thanks