Amana inwall electric heater blows cold air

check heater coil may be faulty may be a faulty thermostat or temp sensor

your diode will read one way and not the other if its correct, not sure what your asking, heater coil could be near back panel remove the lid to check this..

Your question is worded strangely, did you have an electrical fire in the unit? My guess is that you have not kept the filter clean and now you need to take it to a service company for the replacement of the heater's fuseable link.

Your problem could be faulty heater element and or faulty thermostats.
This is a normal problem if the blower is blowing cold air.

a faulty switch it sounds like

the board or the heater need to be replaced

1.check heatar of unit.
2.wireing of heater.
heater not workink.
thermostate also check

1. copressure not working.
2 check spare parts of a/c.
3 wiring

FAULTS ARE STORED WITHIN THE CIRCUIT BOARDS MEMORIE TRY UNPLUGGING IT FOR 2 MINUTES AND PLUGGING IT BACK IN

Yes you could have a bad overload on the heater element which is fairly simple to fix. To test for this pull the heater out and get an ohmeter set it to continuity and check the continuity first through the entire heater element then if there is none pin point the overloads and check to see which one has no continuity.