My AC 1200BTU work in heating 5min. and than stopped

call the technician to check the current draw for the unit
could be a start/run capacitor or compressor going out
What ever you need to know the current draw before anything

seems? (why guess?) (fuses are black/white deal)
3 non related systems failed, hummmmm
check fuses with a walfart $10 meter, on low OHMS> Rx1.

1. 0 ohms is good
2. infinity is bad.

fuses that look good, can in fact be bad. (hair line cracks)
so test them and avoid, SEEMS?
Rear glass heater is a hot wire heater.
if it has 12vdc to the wire and no heat the grid is bad (open)
if no 12v there, then the relay/fuse or switch to it is bad,
the voltmeter finds this in 5min work.
Hazard not working (but are blinkers> dead? on either sided?)
again fuses.
Dash board dead, (cluster) FUSES.

A.C. not working (the FSM and alldata.com cover this)
1: fuse , check fuese
2: if heater fan is dead, so will be AC.
3: A/C clutch not engaging for 6 reasons , ask. for list of tests.
all tests are in the FSM. BTW.

my wild guess, is you are working on car that has not run
right for a long time? accumulated, issues?

check that the heater control (tap ) is being turned on by the controls.. Have an accredited ac mechanic check the ac system .

your heating element could be out. Is this a heat pump type or a heating element?

e4 error code comes for defrost. just remove the cover of your split ac, you shell found a sensor there , check for rat cut.

Clean throttle body...clean idle air control valve...disconnect battery 5min. reconnect battery...let idle...all lights/ac off 5min.

usually that means you have a bad thermistor.
try setting it to low heat timed dry
how long does it run?

when they stop working it blew a fuse or the controler went

there is a thermal fuse inside the dryer it is a one time fuse also there is an ignitor that could be bad

the flashing snowflake is it telling you its in % min delay if it doesnt stop flashing within 5min it may be a bad tstat. if it goes solid and the unit is still not working its probably not the stat