Blower Motor Always Runs at One Speed Only (AZC)

Tests 1 - 3:

Test 4:

SYMPTOM
BLOWER MOTOR ALWAYS RUNS AT ONE SPEED ONLY (AZC)

POSSIBLE CAUSES
- Blower motor control circuit shorted to ground
- Blower motor control circuit shorted to blower motor high driver circuit
- AZC module, fan stuck on one speed only
- Blower motor controller