Operator's Cab

Symptom Problem Solution

Drafts.

Poor air distribution.

Adjust directional air louvers.

Set pressurizer blower switch to "MED" or "LOW".

Inadequate air flow.

Clogged air filters.

Replace filters.

Clogged air inlet screen.

Clean screen.

Evaporator core air flow restricted.

Clean evaporator and housing with compressed air.

Defective blower fan switch.

See your John Deere dealer.

Loose wire connection.

Tighten wire.

Faulty blower fan motor.

See your John Deere dealer.

Water leaking or dripping from evaporator core compartment.

Drain tubes plugged (AC).

Clean drain tubes.

Loose hose clamp.

Tighten clamp.

Drip pan dirty (AC).

Clean evaporator pan and outlet with compressed air.

Pressurizer fan, windshield wiper and/or compressor will not run.

Faulty wiring or loose connections.

Repair or replace wiring.

Defective switch.

See your John Deere dealer.

Defective motor.

See your John Deere dealer.

Strange odors inside operator's cab.

Dirty air filters.

Replace filters.

Drain tubes plugged.

Clean drain tubes.

Evaporator condenser pan dirty.

Clean pan and outlet with compressed air.

Tobacco smoke and tar on evaporator exterior.

Replace filters and clean the exterior of evaporator. (See your John Deere dealer).

NXH8,M68440,L8 -19-10JUL98-1/4


Symptom Problem Solution

Partial frosting and sweating of lines combined with poor cooling.

Compressor belt slipping.

Replace belt.

Loss of refrigerant.

Check sight glass for bubbles and system for leaks.

Restricted or clogged 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.

NXH8,M68440,L8 -19-10JUL98-2/4


Symptom Problem Solution

Failure to cool.

Insufficient blower speed.

Increase blower speed.

Dirty air filters.

Replace filters.

Debris on radiator screen.

Clean screen.

Loose compressor drive belt.

Replace belt.

Dirty air screen.

Clean screen.

Lint or dirt on condenser fins.

Blow out condenser fins with compressed air.

Heater hoses installed backwards.

Install heater hoses correctly. (See your John Deere dealer.)

Condenser is overheating.

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

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

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

Loose wiring connector.

Tighten wire.

Compressor clutch not engaging.

Check wiring or (See your John Deere dealer.)

Refrigerant is lost or extremely low (may have burned thermal fuse or low pressure switch disengages system).

See your John Deere dealer.

Defective temperature control switch.

See your John Deere dealer.

Restriction in refrigerant system. (High pressure switch disengages system).

See your John Deere dealer.)

Expansion valve not functioning.

See your John Deere dealer.

Burned out clutch field or faulty field.

See your John Deere dealer.

Severe restriction in high side.

See your John Deere dealer.

Clogged line strainer.

See your John Deere dealer.

NXH8,M68440,L8 -19-10JUL98-3/4


Symptom Problem Solution

Cab pressure indicator reading at low end of indicator.

Cab blower switch turned off.

Turn switch on.

Door or window not latched.

Latch door or window.

Restricted air filter.

Replace with John Deere activated carbon cab air filter or appropriate substitute. (See Checking And Replacing Cab Air Filters in Chassis section.)

Damaged door or window seals.

Replace damaged seals.

Loss of seal around control linkage, lines, wires, etc.

Seal any openings.

Problem cannot be identified and corrected.

See your John Deere dealer.

Cab pressure indicator reading at high end of indicator.

Damaged seal or pleated filter media on air filter.

Replace with John Deere activated carbon cab air filter or appropriate substitute. (See Checking And Replacing Cab Air Filters in Chassis section.)

Missing or incorrect air filter.

Replace with John Deere activated carbon cab air filter or appropriate substitute. (See Checking And Replacing Cab Air Filters in Chassis section.)

Air filter not seated properly.

Reseat or replace with John Deere activated carbon cab air filter or appropriate substitute. (See Checking And Replacing Cab Air Filters in Chassis section.)

Problem cannot be identified and corrected.

See your John Deere dealer.

NXH8,M68440,L8 -19-10JUL98-4/4