TM-9-2320-283-20-1

TRUCK TRACTOR, LINE HAUL, 50,000 GVWR, 6X4, M915A1

TECHNICAL MANUAL; ORGANIZATIONAL MAINTENANCE PART 1 OF 3

DECEMBER 1983

TM-9-2320-283-20-1 - Page 442 of 926

TM 9-2320-283-20-1

TROUBLESHOOTING.

2-11.

TROUBLESHOOTING PROCEDURES (Continued).

MALFUNCTION

TEST OR INSPECTION

CORRECTIVE ACTION

123.

AIR HORN NOT WORKING.

Step 1.

Check air gage for low pressure reading.

If air pressure is below 20 psi, operate engine until air pressure is back to 125 psi.

See

malfunction 107.

Step 2.

Inspect air lines for damage or clogging.

a. Replace damaged or clogged lines (para 3-163).

b. Replace defective manually operated horn valve (para 3-289).

124.

WINDSHIELD WIPERS NOT WORKING.

Step 1.

Check for air leakage in lines to wiper control valve using a soap solution.

Tighten loose connections and replace damaged lines (para 3-163).

Step 2.

Check to see if wiper mechanical linkage is binding or broken.

Replace defective linkage (para 3-294).

Step 3.

Loosen air lines at wiper motor and turn control to RUN position.

Air should exhaust from line.

a. If no air exhausts, replace control valve (para 3-192).

b. If air exhausts, replace motor (para 3-295).

125.

INTERAXLE DIFFERENTIAL LOCKOUT NOT WORKING.

Step 1.

Check air system pressure.

Charge air system to 105 psi.

2-316