Michigan Mechanic Certification- HVAC
2025/2026 Exam Questions Marking
Scheme New Update | A+ Rated
Cooling system leak diagnosis - 🧠 ANSWER ✔✔Pressure test or dye test
Purpose of a radiator - 🧠 ANSWER ✔✔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
Symptoms of low coolant - 🧠 ANSWER ✔✔Engine overheating and no heat
from the HVAC system
Purpose of the thermostat - 🧠 ANSWER ✔✔The purpose of the thermostat
is to trap the coolant in the engine until it reaches it operating temperature
Cause of low heater output - 🧠 ANSWER ✔✔Low coolant level, clogged
heater core, leaking heater core
Heater core hose routing - 🧠 ANSWER ✔✔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
1
COPYRIGHT©PROFFKERRYMARTIN 2025/2026. YEAR PUBLISHED 2025. COMPANY REGISTRATION NUMBER: 619652435. TERMS OF USE.
PRIVACY STATEMENT. ALL RIGHTS RESERVED
, Heater core operation - 🧠 ANSWER ✔✔The blower motor blows air through
the heater core fins and is warmed through the principle of conduction
Heater control valve purpose - 🧠 ANSWER ✔✔This valve controls the flow
of the coolant to the heater core to control the temperature of the air
desired by the operator
Radiator cap testing - 🧠 ANSWER ✔✔To test pressure test it using an
adapter and a coolant pressure tester and the value marked on the
pressure cap
Reciever drier purpose - 🧠 ANSWER ✔✔May contain a filter or strainer to
catch and trap foreign particles and dirt
Reciever drier location - 🧠 ANSWER ✔✔Located on the high side of the
system between the condenser and the evaporator
Ambient temperature switch purpose - 🧠 ANSWER ✔✔Monitors
temperature by increasing or decreasing with resistance as temperature
changes
Symptoms of a failing ambient temperature switch - 🧠 ANSWER ✔✔A bad
temperature switch could cause an inoperative clutch or input problems
2
COPYRIGHT©PROFFKERRYMARTIN 2025/2026. YEAR PUBLISHED 2025. COMPANY REGISTRATION NUMBER: 619652435. TERMS OF USE.
PRIVACY STATEMENT. ALL RIGHTS RESERVED
2025/2026 Exam Questions Marking
Scheme New Update | A+ Rated
Cooling system leak diagnosis - 🧠 ANSWER ✔✔Pressure test or dye test
Purpose of a radiator - 🧠 ANSWER ✔✔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
Symptoms of low coolant - 🧠 ANSWER ✔✔Engine overheating and no heat
from the HVAC system
Purpose of the thermostat - 🧠 ANSWER ✔✔The purpose of the thermostat
is to trap the coolant in the engine until it reaches it operating temperature
Cause of low heater output - 🧠 ANSWER ✔✔Low coolant level, clogged
heater core, leaking heater core
Heater core hose routing - 🧠 ANSWER ✔✔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
1
COPYRIGHT©PROFFKERRYMARTIN 2025/2026. YEAR PUBLISHED 2025. COMPANY REGISTRATION NUMBER: 619652435. TERMS OF USE.
PRIVACY STATEMENT. ALL RIGHTS RESERVED
, Heater core operation - 🧠 ANSWER ✔✔The blower motor blows air through
the heater core fins and is warmed through the principle of conduction
Heater control valve purpose - 🧠 ANSWER ✔✔This valve controls the flow
of the coolant to the heater core to control the temperature of the air
desired by the operator
Radiator cap testing - 🧠 ANSWER ✔✔To test pressure test it using an
adapter and a coolant pressure tester and the value marked on the
pressure cap
Reciever drier purpose - 🧠 ANSWER ✔✔May contain a filter or strainer to
catch and trap foreign particles and dirt
Reciever drier location - 🧠 ANSWER ✔✔Located on the high side of the
system between the condenser and the evaporator
Ambient temperature switch purpose - 🧠 ANSWER ✔✔Monitors
temperature by increasing or decreasing with resistance as temperature
changes
Symptoms of a failing ambient temperature switch - 🧠 ANSWER ✔✔A bad
temperature switch could cause an inoperative clutch or input problems
2
COPYRIGHT©PROFFKERRYMARTIN 2025/2026. YEAR PUBLISHED 2025. COMPANY REGISTRATION NUMBER: 619652435. TERMS OF USE.
PRIVACY STATEMENT. ALL RIGHTS RESERVED
