MICHIGAN MECHANIC CERTIFICATION- HVAC EXAM QUESTIONS AND
CORRECT DETAILED ANSWERS WITH EXPLANATIONS (VERIFIED
ANSWERS) A NEW UPDATED VERSION LATEST| GUARANTEED A+
1. Cooling system leak Pressure test or dye test
diagnosis
2. Purpose of a radiator The purpose of the radiator is to dissipate heat
that is picked up by coolant in the engine into
the air passing through its fins and tubes
3. Symptoms of low coolant Engine overheating and no heat from the
HVAC system
4. Purpose of the The purpose of the thermostat is to trap the
thermostat coolant in the engine until it reaches it
operating temperature
5. Cause of low heater Low coolant level, clogged heater core,
output leaking heater core
6. Heater core hose routing The supply hose from the heater core should
run from the closed side of the thermostat to
the heater core and the return hose should run
, from the heater core to the engine
7. Heater core operation The blower motor blows air through the heater
core fins and is warmed through the principle
of conduction
8. Heater control valve This valve controls the flow of the coolant to
purpose the heater core to control the temperature of
the air desired by the operator
9. Radiator cap testing To test pressure test it using an adapter and a
coolant pressure tester and the value marked
on the pressure cap
10. Reciever drier purpose May contain a filter or strainer to catch and
trap foreign particles and dirt
11. Reciever drier location Located on the high side of the system
between the condenser and the evaporator
12. Ambient temperature Monitors temperature by increasing or
switch purpose decreasing with resistance as temperature
changes
13. Symptoms of a failing A bad temperature switch could cause an
ambient temperature inoperative clutch or input problems
switch
14. Orifice expansion tube Has a valve that can vary the size of the
operation opening to allow more or less liquid refrigerant
through to the evaporator
CORRECT DETAILED ANSWERS WITH EXPLANATIONS (VERIFIED
ANSWERS) A NEW UPDATED VERSION LATEST| GUARANTEED A+
1. Cooling system leak Pressure test or dye test
diagnosis
2. Purpose of a radiator The purpose of the radiator is to dissipate heat
that is picked up by coolant in the engine into
the air passing through its fins and tubes
3. Symptoms of low coolant Engine overheating and no heat from the
HVAC system
4. Purpose of the The purpose of the thermostat is to trap the
thermostat coolant in the engine until it reaches it
operating temperature
5. Cause of low heater Low coolant level, clogged heater core,
output leaking heater core
6. Heater core hose routing The supply hose from the heater core should
run from the closed side of the thermostat to
the heater core and the return hose should run
, from the heater core to the engine
7. Heater core operation The blower motor blows air through the heater
core fins and is warmed through the principle
of conduction
8. Heater control valve This valve controls the flow of the coolant to
purpose the heater core to control the temperature of
the air desired by the operator
9. Radiator cap testing To test pressure test it using an adapter and a
coolant pressure tester and the value marked
on the pressure cap
10. Reciever drier purpose May contain a filter or strainer to catch and
trap foreign particles and dirt
11. Reciever drier location Located on the high side of the system
between the condenser and the evaporator
12. Ambient temperature Monitors temperature by increasing or
switch purpose decreasing with resistance as temperature
changes
13. Symptoms of a failing A bad temperature switch could cause an
ambient temperature inoperative clutch or input problems
switch
14. Orifice expansion tube Has a valve that can vary the size of the
operation opening to allow more or less liquid refrigerant
through to the evaporator
