FAN SPEED DOES NOT DECREASE FROM HIGH TO LOW SPEED.

TM 9-2320-364-34-1

2-13. HYDRAULIC SYSTEM TROUBLESHOOTING (CONT).

5. FAN SPEED DOES NOT DECREASE FROM HIGH TO LOW SPEED.

INITIAL SETUP

Personnel Required

Tools and Special Tools

Two

Tool Kit, General Mechanic's

(Item 240, Appendix F)

References

Analyzer Set, STE/ICE-R (Optional)

TM 9-2320-364-10

(Item 15, Appendix F)

TM 9-2320-364-20

Multimeter (Item 140, Appendix F)

TM 9-4910-571-12&P

Pan, Drain 4 gal (Item 144, Appendix F)

Materials/Parts

Equipment Condition

Oil, Hydraulic (Item 34, Appendix B)

Engine OFF, (TM 9-2320-364-10)

Sealing Compound (Item 62, Appendix B)

Parking brake applied, (TM 9-2320-364-10)

Lockwashers (4) (Item 266, Appendix E)

Wheels chocked, (TM 9-2320-364-10)

Lockwashers (30) (Item 282, Appendix E)

Coolant temperature at 190F, (88C)

Parts Kit, Seal (Item 412, Appendix E)

Parts Kit, Seal (Item 408, Appendix E)

START

KNOWN INFO

TEST OPTIONS

Audible inspection.

Unit Troubleshooting

Does fan speed lower when

tasks completed.

hydraulic selector switch is

22 to 28 vdc to high speed fan

REASON FOR QUESTION

turned to AUTO?

lockout solenoid valve is

Certain combinations of failures

present.

will determine the point where

troubleshooting procedures

POSSIBLE PROBLEMS

should begin.

EPAC controller faulty.

Fan control solenoid

valve faulty.

High speed fan lockout solenoid

valve faulty.

High speed fan lockout

differential pressure sensing

Go to Step 3 of

valve faulty.

this Fault.

YES

2-214