srplus
Walked with the Dinosaurs
I got tired of looking for this information disjointedly and decided to put it all together in one place... after some previous diagnostics and lots of searching the forums, i got to the point where i found out my magnetic clutch on my A/C compressor was not engaging. NOW WHY? there will be a lottery with bets being placed on what different components are bad or if it is a short or breaker. jump right in here and share your experience (or like me - lack of it)... payback is happy camper with only the parts needing replacement having to be replaced and a functioning A/C system.
for me, i am hoping that the info on AC-35 is it - turn knob on AC amplifier (a DUH-UH i never thought of, see below). Something else to DEFINITELY check is the circuit breaker in the fuse panel... reset if necessary. If it kicks again you are in for loads of fun.
The following is a 'sort of' table of a of contents of the Air Conditioning Chapter from the "Land Cruiser Heavy Duty Repair Manual - Chassis and Body ’84 – ’90" (Low Resolution Manual is available as a HUGE file - 101,850 KB’s for download at http://www.birfield.com/downloads-cats-1-0-10.html - download it while you sleep! or the high resolution one, while you turn grey):
OFF TO THE RACES (WITH A/C) - pages first . then topic . then synopsis
AC-2 - 3 TROUBLESHOOTING A/C –
AC-2 Problem: no cooling or warm air page; AC-3 More warm air and all other problems.
MY PROBLEM: Magnetic Clutch does not engage
(Possible Cause - Remedy - Page #)
a) A/C fuse blown – replace fuse & check for short - AC9 – 14
b) Magnetic clutch faulty - check magnetic clutch – AC-24
c) A/C switch faulty - check A/C switch - AC-33
d) Temp. control resistor faulty - check resistor - AC-34
e) Thermistor faulty - check thermistor - AC-31
f) A/C amplifier faulty - check amplifier - AC-35
g) Wiring or Ground faulty - repair as necessary - AC9 – 14
h) Refrigerant empty - check refrigerant pressure - AC-16
i) Heater relay faulty - check heater relay - AC9 – 14
j) circuit breaker faulty - check circuit breaker - AC9 – 14 (doesn't really explain how to here in wiring diagram section)
k) pressure switch faulty - check pressure switch - AC-35
AC-4 – 8 checking refrigerant with manifold gauge
AC-9 is electrical diagram of A/C for FJ60.
AC-10 - AC-14 Electricals for other 60’s & 70’s models.
AC-15 - belts and beginning diagnosis.
AC-16 – AC-20 Checking and charging system. Amount of Refrigerant
Is there Correct Amount of Refrigerant in system?
Operate A/C at Max cooling for several minutes. Check amount of refrigerant thru sight glass in receiver. (This is for R-12 and I assume is the same for 134A.)
1) bubbles present in sight glass – insufficient refrigerant – check for leak with gas tester.
2) no bubbles in sight glass – none, too much or sufficient – Refer to 3 & 4
3) no temperature difference between compressor inlet and outlet – empty or nearly empty – evacuate and charge system. Then check for leaks with gas checker.
4) Temperature difference between compressor inlet and outlet is noticeably different – proper or too much refrigerant (could be slightly low too). See 5 & 6
5) Immediately after A/C is turned off, refrigerant in sight window turns clear – too much refrigerant – discharge excess refrigerant to specified amount.
6) Immediately after A/C is turned off, refrigerant in sight window foams and then turns clear – LEAVE IT ALONE, refrigerant is not your issue.
Amount of refrigerant to fill system correctly is given for R-12 so i am not sure if these weights are accurate for other replacement refrigerants.
AC-20 – AC-21 Performance Tests of AC system. (DUH-UH. does the air feel cold?) These are technical tests.
AC-21- Check Relative Humidity
AC-22 – AC-23 System Components of A/C - Schematics
AC 24 - AC Compressor & Magnetic Clutch. Magnetic Clutch Troubleshooting:
a) inspect pressure plate & rotor for signs of oil
b) check clutch bearings for noise & grease leakage
c) using ohm meter, measure resistance of the stator coil between the clutch lead & ground. If resistance is not within tolerance, replace the coil. 3.7+/- 0.2 OHMs @ 68 degrees F.
AC-25 - 3F Engine Series
AC-26 - 2H Engine Series & removal of compressor
AC-27 - Installation of compressor
AC-28 - Condenser check, removal & installation
AC-29 - Receiver inspection, removal & installation. Front Cooling Unit Inspection of exansion valve
AC-30 - Removal & disassembly of Front Cooling Unit
AC-31 - Removal of components from evaporator & its inspection. Inspection of Thermistor: must put the thermistor in different baths of cold water and measure resistance in ohms… must fall within range on chart. Assembly of front cooling Unit.
AC-32 - Assembly of front cooling Unit. Installation of front cooling unit.
AC-33 - Inspection Expansion Valve (FACTORY RECALL ON THIS PART ON FJ80's – VIN SPECIFIC – USA; not 60's or 62's as previously stated!) 60 Series A/C switch inspection – disconnect negative battery cable. Disconnect A/C switch connector. Check for continuity with Ohmmeter on terminals for each switch position as shown in table. If there is no continuity, replace switch.
AC-34 - Temp Control Resistor (70 Series only); Refrigerant Lines inspection & replacement
AC-35 - Pressure Switch Inspection & check – see pages AC-22, 23: remove glove box (except dual A/C); disconnect lead wires of A/C harness. Use ohmmeter to check continuity of two terminals of the switch. Ohmmeter must indicate zero ohms. If there is no continuity, replace the pressure switch.
AC-35 - Air Conditioner Amplifier – run engine to operate the A/C. Check that the magnetic clutch disengages at 600 – 700 rpm. If the cut-off rpm is too high: turn adjusting knob clockwise to adjust… if too cut-off rpm is too low: turn adjusting knob counter clockwise to adjust. Does not explain how to test if it works or needs to be replaced except i guess it either does or it doesn't.
AC-36 – AC-37 - Rear cooling unit (60 series Dual A/C) Removal & disassembly; Magnetic Valve Inspection (60 series Dual A/C)
AC-38 - 39 - A/C Relay: inspection – involves ohmmeter and diagrams w/ info on continuity or not and section for Aussie models; real A/C relay for Dual A/C systems
AC-40 - Vacuum Switching Valve – VSV Inspection:
1) disconnect vacuum hoses and electrical connector from VSV. (Position VSV in front of you with the two tubes to the left and electrical connection closest to you. The tube to your left is tube B; the tube closest to center of unit with electrical connector to right is tube A.)
2) Check vacuum circuit continuity by blowing into pipe (pipe nearest center of unit to left of electrical connection)
a) connect VSV electrical terminals correctly (negative is closest to body of VSV, positive is furthest from body of VSV)
b) blow into pipe A and insure that air comes out of pipe B
c) disconnect electric from battery!
d) blow into pipe A and insure that air comes out filter C (furthermost outlet on right end of unit, to right of electrical connection that should be disconnected) > air should not come out of tube B! if this is not how the VSV operates when connected and disconnected from battery source – Replace VSV.
3) Check for short circuit: take ohmmeter probe from positive and negative terminals of VSV to the body of the VSV (metal) and check that there is no continuity. If there is continuity then you have a short and must Replace VSV.
4) Check for open Circuit: using ohmmeter check measure of resistance between two electrical terminals of the VSV. Resistance between 37 – 44 ohms at 68 Degrees F. If not: Replace VSV.
for me, i am hoping that the info on AC-35 is it - turn knob on AC amplifier (a DUH-UH i never thought of, see below). Something else to DEFINITELY check is the circuit breaker in the fuse panel... reset if necessary. If it kicks again you are in for loads of fun.
STAY COOL!
The following is a 'sort of' table of a of contents of the Air Conditioning Chapter from the "Land Cruiser Heavy Duty Repair Manual - Chassis and Body ’84 – ’90" (Low Resolution Manual is available as a HUGE file - 101,850 KB’s for download at http://www.birfield.com/downloads-cats-1-0-10.html - download it while you sleep! or the high resolution one, while you turn grey):
For those of you in the USA, please note that toyota has a recall on the expansion valve on FJ80's (NOT 60's or 62's) VIN specific - see notes below AND DO SEARCH FOR RECALLS. Your fj80 may be eligible to have somebody from your Toyota Dealership do some of this stuff for free if the car has not had this part already replaced by Toyota.
OFF TO THE RACES (WITH A/C) - pages first . then topic . then synopsis
AC-2 - 3 TROUBLESHOOTING A/C –
AC-2 Problem: no cooling or warm air page; AC-3 More warm air and all other problems.
MY PROBLEM: Magnetic Clutch does not engage
(Possible Cause - Remedy - Page #)
a) A/C fuse blown – replace fuse & check for short - AC9 – 14
b) Magnetic clutch faulty - check magnetic clutch – AC-24
c) A/C switch faulty - check A/C switch - AC-33
d) Temp. control resistor faulty - check resistor - AC-34
e) Thermistor faulty - check thermistor - AC-31
f) A/C amplifier faulty - check amplifier - AC-35
g) Wiring or Ground faulty - repair as necessary - AC9 – 14
h) Refrigerant empty - check refrigerant pressure - AC-16
i) Heater relay faulty - check heater relay - AC9 – 14
j) circuit breaker faulty - check circuit breaker - AC9 – 14 (doesn't really explain how to here in wiring diagram section)
k) pressure switch faulty - check pressure switch - AC-35
AC-4 – 8 checking refrigerant with manifold gauge
AC-9 is electrical diagram of A/C for FJ60.
AC-10 - AC-14 Electricals for other 60’s & 70’s models.
AC-15 - belts and beginning diagnosis.
AC-16 – AC-20 Checking and charging system. Amount of Refrigerant
Is there Correct Amount of Refrigerant in system?
Operate A/C at Max cooling for several minutes. Check amount of refrigerant thru sight glass in receiver. (This is for R-12 and I assume is the same for 134A.)
1) bubbles present in sight glass – insufficient refrigerant – check for leak with gas tester.
2) no bubbles in sight glass – none, too much or sufficient – Refer to 3 & 4
3) no temperature difference between compressor inlet and outlet – empty or nearly empty – evacuate and charge system. Then check for leaks with gas checker.
4) Temperature difference between compressor inlet and outlet is noticeably different – proper or too much refrigerant (could be slightly low too). See 5 & 6
5) Immediately after A/C is turned off, refrigerant in sight window turns clear – too much refrigerant – discharge excess refrigerant to specified amount.
6) Immediately after A/C is turned off, refrigerant in sight window foams and then turns clear – LEAVE IT ALONE, refrigerant is not your issue.
Amount of refrigerant to fill system correctly is given for R-12 so i am not sure if these weights are accurate for other replacement refrigerants.
AC-20 – AC-21 Performance Tests of AC system. (DUH-UH. does the air feel cold?) These are technical tests.
AC-21- Check Relative Humidity
AC-22 – AC-23 System Components of A/C - Schematics
AC 24 - AC Compressor & Magnetic Clutch. Magnetic Clutch Troubleshooting:
a) inspect pressure plate & rotor for signs of oil
b) check clutch bearings for noise & grease leakage
c) using ohm meter, measure resistance of the stator coil between the clutch lead & ground. If resistance is not within tolerance, replace the coil. 3.7+/- 0.2 OHMs @ 68 degrees F.
AC-25 - 3F Engine Series
AC-26 - 2H Engine Series & removal of compressor
AC-27 - Installation of compressor
AC-28 - Condenser check, removal & installation
AC-29 - Receiver inspection, removal & installation. Front Cooling Unit Inspection of exansion valve
AC-30 - Removal & disassembly of Front Cooling Unit
AC-31 - Removal of components from evaporator & its inspection. Inspection of Thermistor: must put the thermistor in different baths of cold water and measure resistance in ohms… must fall within range on chart. Assembly of front cooling Unit.
AC-32 - Assembly of front cooling Unit. Installation of front cooling unit.
AC-33 - Inspection Expansion Valve (FACTORY RECALL ON THIS PART ON FJ80's – VIN SPECIFIC – USA; not 60's or 62's as previously stated!) 60 Series A/C switch inspection – disconnect negative battery cable. Disconnect A/C switch connector. Check for continuity with Ohmmeter on terminals for each switch position as shown in table. If there is no continuity, replace switch.
AC-34 - Temp Control Resistor (70 Series only); Refrigerant Lines inspection & replacement
AC-35 - Pressure Switch Inspection & check – see pages AC-22, 23: remove glove box (except dual A/C); disconnect lead wires of A/C harness. Use ohmmeter to check continuity of two terminals of the switch. Ohmmeter must indicate zero ohms. If there is no continuity, replace the pressure switch.
AC-35 - Air Conditioner Amplifier – run engine to operate the A/C. Check that the magnetic clutch disengages at 600 – 700 rpm. If the cut-off rpm is too high: turn adjusting knob clockwise to adjust… if too cut-off rpm is too low: turn adjusting knob counter clockwise to adjust. Does not explain how to test if it works or needs to be replaced except i guess it either does or it doesn't.
AC-36 – AC-37 - Rear cooling unit (60 series Dual A/C) Removal & disassembly; Magnetic Valve Inspection (60 series Dual A/C)
AC-38 - 39 - A/C Relay: inspection – involves ohmmeter and diagrams w/ info on continuity or not and section for Aussie models; real A/C relay for Dual A/C systems
AC-40 - Vacuum Switching Valve – VSV Inspection:
1) disconnect vacuum hoses and electrical connector from VSV. (Position VSV in front of you with the two tubes to the left and electrical connection closest to you. The tube to your left is tube B; the tube closest to center of unit with electrical connector to right is tube A.)
2) Check vacuum circuit continuity by blowing into pipe (pipe nearest center of unit to left of electrical connection)
a) connect VSV electrical terminals correctly (negative is closest to body of VSV, positive is furthest from body of VSV)
b) blow into pipe A and insure that air comes out of pipe B
c) disconnect electric from battery!
d) blow into pipe A and insure that air comes out filter C (furthermost outlet on right end of unit, to right of electrical connection that should be disconnected) > air should not come out of tube B! if this is not how the VSV operates when connected and disconnected from battery source – Replace VSV.
3) Check for short circuit: take ohmmeter probe from positive and negative terminals of VSV to the body of the VSV (metal) and check that there is no continuity. If there is continuity then you have a short and must Replace VSV.
4) Check for open Circuit: using ohmmeter check measure of resistance between two electrical terminals of the VSV. Resistance between 37 – 44 ohms at 68 Degrees F. If not: Replace VSV.
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