OMFH318462

Air Conditioning

Symptom	Problem	Solution
System Will Not Produce Sufficient Cooling	Fan speed switch off	Press setpoint adjust switch on armrest console and adjust blower speed up or down with selection dial.
	Compressor not functioning (both the large and small air-conditioning hoses, exiting right-hand rear corner of cab, are at the same temperature)	See your John Deere dealer.
	High-pressure switch open. Insufficient air flow across condenser	Clean condenser. Check rotary wand duct for obstruction. Clean air screen. See your John Deere dealer.
	Low-pressure switch open. Insufficient air flow across evaporator	Clean cab filters. Check cab fan operation. See your John Deere dealer.
	Low-pressure switch open. Low outside air temperature	Move temperature control to warmer setting.
	Low-pressure switch open. Insufficient refrigerant level (bubbles in sight glass)	See your John Deere dealer.
	Heater valve partially on (with temperature knob set for maximum cooling, feel both heater hoses exiting right-hand rear corner of cab. If both are warm, valve is open)	See your John Deere dealer.
	Insufficient blower speed	Increase blower speed.
	Debris on radiator screen	Clean screen.
	Compressor clutch not engaging	See your John Deere dealer.
	Condenser is overheating	Clean screens, cores and fins of condenser, oil cooler, and radiator.
	Burned out clutch field or faulty field	See your John Deere dealer.
	Faulty high pressure or low pressure switches	Replace switches.
	Faulty A/C evaporator thermostat sensor	Replace A/C evaporator thermostat sensor.
	Recirculating fan disconnected	Check connectors at fan switch.
	Compressor partially or completely seized	Remove compressor for service or replacement.
	Dirty filters	Clean filters.
	Broken or disconnected electrical wire	Check all terminals for loose connections; check wiring for hidden breaks.
	Broken or disconnected cab ground wire	Check ground wire to see if loose, broken, or disconnected.
	Expansion valve stuck in open position	Replace expansion valve.
	Expansion valve stuck shut	Replace expansion valve.
	Broken refrigerant line	Examine all lines for evidence of breakage by external stress of rubbing wear.
	Leak in system	Evacuate system, apply static charge, leak test system, and repair leak as necessary.
	Restriction in refrigerant system	Check for kinked hoses.
	Restriction in receiver/dryer	See your John Deere dealer.
	Restriction in expansion valve	See your John Deere dealer.
	Compressor shaft seal leaking	Replace the compressor shaft seal.
	Excessive moisture in system, causing expansion valve freeze up	Drain and recharge. Replace receiver-dryer.
	Clogged cab roof inlet panel	Remove and clean.
	Evaporator fins clogged	Blow out evaporator fins with compressed air.
	Too little refrigerant in system	Recharge system.
	Clogged screen in receiver-dryer	Discharge system; replace receiver-dryer. Then evacuate and charge system.
	Excessive moisture in system	Discharge system; replace receiver-dryer. Then evacuate and charge system.
	Air in system	Discharge, evacuate, and charge system.

Hissing Noise At Expansion Valve

Loss of refrigerant

Check sight glass for bubbles and system for leaks. See your John Deere dealer.

Restriction in refrigerant system

Check for kinks in hoses.

Check receiver-dryer for uniformity of temperature. If temperature is not uniform, see your John Deere dealer.

Partial Frosting and Sweating of Lines Combined With Poor Cooling	Loss of refrigerant	Check sight glass for bubbles and 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.

Air Conditioning System Too Noisy	Loose or excessively worn drive belt.	Tighten or replace as necessary.
	Noisy clutch	Remove clutch for service or replacement as necessary.
	Compressor noisy	Check mountings and repair; remove compressor for service or replacement.
	Excessive charge in system	Discharge excess refrigerant until high-pressure gauge drops within specifications.
	Low charge in system	Check system for leaks; charge system.
	Excessive moisture in system	Replace receiver-dryer; evacuate and charge system.

Air Conditioning System Cools Intermittently	Compressor clutch slipping	Slippage over a prolonged period will require that clutch be removed for service; may require adjustment for proper spacing.
	Unit icing up may be caused by excessive moisture in system, inoperative expansion valve, or faulty thermostat	Replace expansion valve; replace receiver-dryer if excess moisture is present; replace thermostat.
	Thermostat defective	Replace thermostat.
	Defective blower switch or blower motor	Remove defective part for service or replacement.
	Partially open, improper ground, or loose connection in compressor clutch coil or solenoid	Check connections or remove clutch coil or solenoid for service or replacement.

Compressor clutch cycles excessively or compressor stays off up to 15 minutes

Evaporator icing

Adjust controls correctly. (See Operator's Station section.) Open louvers. Clean filters. Move knob to warmer setting.

Bad smell (foul odor) in cab

Plugged drain tube. Dirty filters. Dirty cab

Blow out condensate tube. Clean filters. Vacuum out cab.

Be certain weep valve in condensate drain tube is installed.

RC48509,00005C3-19-20120815