Table 4-2. Unit Troubleshooting-continued -706880266

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

4-2. Unit Troubleshooting-Continued

MALFUNCTION

TEST OR INSPECTION

CORRECTIVE ACTION

ELECTRICAL SYSTEM - AERIAL CONTROL PANEL - Continued

16 FLOW MINDER (GALLONS-PER-MINUTE) METER DOES NOT FUNCTION PROPERLY

Step 1. Check for +12V at aerial buss.

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

Step 2. Check fuse between aerial panel terminal strip and flow minder unit.

Replace fuse (see para 4-9.4).

Step 3. Check wiring for continuity.

Replace wire (see para 4-9.4).

Step 4. Check sender wire for continuity.

Replace wire (see para 4-9.4).

Step 5. With water flowing through aerial nozzle, check for display on gallons-per-minute meter.

If no response, replace sender (see para 4-184).

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

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

Step 1. Check that Murphy load sensor switch is set at 1950 psi.

Adjust load sensor switch (see para 4-187).

Step 2. Check electric horn relay for proper operation.

Replace relay (see para 4-187).

Step 3. Check contacts on Murphy load sensor switch make good contact.

Replace Murphy load sensor switch (see para 4-187).

Step 4. Check electric horn for proper operation.

Replace horn (see para 4-187).

4-137