Jeep Repair: Jeep Grand Che. Ltd. 3 issues please help, left turn signal, power brake booster

Question
I am having 3 issues the first is the left turn signal only works when it wants mainly when it is cold out, I have checked the bulb and that is not the problem. 2. I only have heat on the driver side the passenger side only blows very cold air I did the test for the AZC and only came up with the historical codes 50, 54, & 56. I think it is a blend door but how would i go about fixing it. and last there is a hissing noise coming from my brakes i think it might be the power brake booster. Is there a way to tell for sure and how can i tell if the master cylinder is still good? I have had in to an independent mechanic and they said around 1500-2000 for everything. I am in Minnesota so i really need working heat.

Answer
the no heat  yes is blend air door  U will need to remove the dash to fix   buy a manual for instructions. A booster prob would be lack of assist when u brake  the hissing would be the movement of the booster more then likely. If the master cly was bad  U would not be stopping..
for 2k u can get that done at a dealer.  What was said about the blinker?  multifunction switch?