Table 4-2. Unit Troubleshooting-continued -706880267

TM 5-4210-233-14&P-1

4-2. Unit Troubleshooting-Continued

MALFUNCTION

TEST OR INSPECTION

CORRECTIVE ACTION

ELECTRICAL SYSTEM - AERIAL CONTROL PANEL - Continued

17 OVERLOAD ALARM DOES NOT SOUND WHEN HYDRAULIC SYSTEM IS AT 1950 PSI - Continued

Step 5. Check wiring for continuity.

Replace wire (see para 4-9.4).

Step 6. Check aerial circuit breaker #6 for +12V.

Replace breaker (see para 4-99).

Step 7. Refer to "+12 volts not present at aerial master buss" troubleshooting procedure.

Step 8. Refer to "swivel assembly slip ring contact interrupted" troubleshooting procedure.

18 OVERLOAD ALARM SOUNDS CONTINUOUSLY WHILE HYDRAULIC SYSTEM PRESSURE

IS BELOW 1950 PSI

(Refer to Electrical Wiring Diagrams, Appendix H, Sheet 10 of 16.)

Step 1. Check relay for proper operation.

Replace relay (see para 4-9.4).

Step 2. Check Murphy load sensor switch for proper operation.

Replace switch (see para 4-187).

19 AERIAL MONITOR/NOZZLE DOES NOT RESPOND TO UPPER CONTROL BOX

(Refer to Electrical Wiring Diagrams, Appendix H, Sheet 12 of 16.)

Step 1. Check automotive override relay (R7) for proper operation.

Replace relay (see para 4-9.4).

Step 2 Check wires from relay box to control box for continuity.

Replace wire (see para 4-9.4).

Step 3. Check switches for proper operation.

Replace switch (see para 4-203).

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