Cab Air Troubleshooting - MacDon M1170 Operator's Manual

7.7 Cab Air Troubleshooting

Problem
Symptom: The blower fan will not run.
Burned out motor
Burned out switch
Motor shaft tight or bearings worn
Faulty wiring—loose or broken
Blower rotors in contact with housing
Burned out motor
Symptom: The blower fan is operating, but air doesn't blow into the cab.
Dirty fresh air filter
Dirty recirculating air filter
Evaporator clogged
Air flow passage blocked
Symptom: Heater is not heating.
Heater shut-off valve at engine closed
Defective thermostat in engine water
outlet manifold
Heater temperature control defective
No thermostat in engine water outlet
manifold
Symptom: Air louvers emitting odor.
Plugged drainage hose
Dirty filters
Symptom: Air conditioning is not cooling.
Low refrigerant level
Clutch coil burned out or disconnected Contact Dealer.
Blower motor disconnected or
burned out
Switch contacts in thermostat burned
excessively, or sensing element
defective
Compressor partially or
completely seized
Condenser fins plugged
214733
TROUBLESHOOTING
Solution
Contact Dealer.
Contact Dealer.
Contact Dealer.
Contact Dealer.
Contact Dealer.
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Clean fresh air filter.
Clean return air filter.
Clean evaporator.
Remove blockage.
Open valve.
Replace thermostat.
Replace control.
Install thermostat.
Blow out hose with compressed air.
Clean filters.
Add refrigerant.
Contact Dealer.
Replace thermostat.
Remove compressor for service or
replacement.
Clean condenser.
413
Section
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Inspecting and Cleaning Fresh Air
Intake Filter Element, page 299
5.9.1 Servicing Return Air Filter, page
304
Cleaning Air Conditioning (A/C)
Evaporator Core, page 355
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3.10.1 Heater Shut-Off Valve, page 59
Contact Dealer.
Contact Dealer.
Contact Dealer.
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Contact Dealer.
Contact Dealer.
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Contact Dealer.
Contact Dealer.
Cleaning Left Cooling Module, page
306
Revision A