Heater and A/C System Troubleshooting (Cab)

Symptom Problem Solution

All cab electrical switches do not work

Loose, defective or blown fusible link.

See your John Deere dealer.

Blower malfunctioning

Blower does not work.

Check both blower fuses.

Blower operates only in purge position

One of two fuses blown.

Replace fuse.

Blown blower resistance assembly.

See your John Deere dealer.

Heater does not work

Low coolant level.

Check coolant level; add if necessary.

Faulty thermostat.

See your John Deere dealer.

Heater control valve not functioning properly.

See your John Deere dealer.

Heater core or hoses clogged or damaged.

Flush cooling system. (See your John Deere dealer.)

Replace heater core or hoses. (See your John Deere dealer.)

Air conditioning does not work

Fan belt loose or slipping.

Check belt tension. Replace belt if necessary.

Blown fuse.

Replace fuse.

Defective switch.

See your John Deere dealer.

Faulty wiring or loose connections.

See your John Deere dealer.

Defective compressor clutch.

See your John Deere dealer.

Drafts

Poor air distribution

Adjust directional air louvers.

Set blower switch to medium or low position.

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Symptom Problem Solution

Inadequate air flow

Clogged air filters.

Clean filters.

Evaporator core air flow restricted.

Clean evaporator and housing with compressed air.

Faulty blower fan motors.

See your John Deere dealer.

Defective blower switch.

See your John Deere dealer.

Faulty wiring or loose connections.

See your John Deere dealer.

Water leaking or dripping from evaporator core compartment

Loose hose clamp.

Tighten clamp.

A/C drip pan dirty.

Clean evaporator pan and outlet with compressed air.

A/C drain tubes plugged.

Clean drain tubes.

Strange odors inside operator cab

Dirty air filters.

Clean filters.

Evaporator condenser pan dirty.

Clean pan and outlet with compressed air.

Drain tubes plugged.

Clean drain tubes.

Tobacco smoke and tar on evaporator exterior.

Clean filters.

Partial frosting and sweating of lines combined with poor cooling

Fan belt slipping.

Check belt tension. Replace belt if necessary.

Loss of refrigerant.

Check system for leaks. See your John Deere dealer.

Restricted or clogged liquid line.

See your John Deere dealer.

Expansion valve malfunctioning.

See your John Deere dealer.

Ice flecks blowing from evaporator

Control dial set too low.

Adjust the temperature control to a warmer position.

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Symptom Problem Solution

Failure to cool

Insufficient blower speed.

Increase blower speed.

Dirty air filters.

Clean filters.

Debris on front grille.

Clean front grille.

Lint or dirt on condenser fins.

Blow out condenser fins with compressed air.

Refrigerant is lost or extremely low.

See your John Deere dealer.

Loose fan belt.

Check belt tension. Replace belt if necessary.

Compressor clutch not engaging.

See your John Deere dealer.

Expansion valve not functioning.

See your John Deere dealer.

Restriction in refrigerant system.

See your John Deere dealer.

Faulty wiring or loose connections.

See your John Deere dealer.

Defective temperature control switch.

See your John Deere dealer.

Outside temperature too low, below 21°C (70°F).

Wait until day gets warmer. If there is a malfunction in system, see your John Deere dealer.

Condenser is overheating.

Clean condenser screens, cores and fins of condenser and radiator.

Severe restriction in high side.

See your John Deere dealer.

Burned out clutch field or faulty field.

See your John Deere dealer.

Short circuit in control circuit or failure of a switch in circuit.

See your John Deere dealer.

Hissing noise at expansion valve

Loss of refrigerant.

Check system for leaks. See your John Deere dealer.

Restriction in refrigerant system.

Check for kinks in hoses.

Check receiver-dryer for uniformity of temperature. See your John Deere dealer.

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