Table 4-2. Unit Troubleshooting-continued -706880244

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

Table 4-2. Unit Troubleshooting - Continued

MALFUNCTION

TEST OR INSPECTION

CORRECTIVE ACTION

ELECTRICAL SYSTEM - PTO

CAB SWITCH WILL NOT ENGAGE AERIAL PTO WITH PARK BRAKE ON, SHIFT SELECTOR IN

N (NEUTRAL), AND AERIAL MASTER CIRCUIT ON

(Refer to Electrical Wiring Diagrams, Appendix H, Sheet 3 of 16.)

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

If +12V is present at aerial buss, go on to Step 2..

If +12V is not present at aerial buss, refer to "+12 volts not present at aerial master buss"

troubleshooting procedure.

Step 2. Check aerial master fuse for continuity.

Replace fuse (see para 4-9.4).

Step 3. Test aerial PTO switch for proper operation.

Replace aerial PTO switch (see para 4-94).

Step 4. Check CRY054 for continuity between terminals 6 and 9 while relay is energized.

(To be energized, parking brake must be on, transmission shift selector in N (neutral),

and battery switch on.)

Replace CRY054 (see para 4-9.4).

Step 5. Check wire 1206 for continuity between CRY054 and PTO solenoid valve.

Replace wire (see para 4-9.4).

Step 6. Check PTO solenoid valve for proper operation.

Replace PTO solenoid valve (see para 4-9.4).

PTO ENGAGED LIGHT WILL NOT ILLUMINATE

(Refer to Electrical Wiring Diagram, Appendix H, Sheet 3 of 16.)

Step 1. With diverter valve in outrigger position, operate outrigger control levers.

If outriggers function, go on to Step 2.

If outriggers do not function, refer to "cab switch will not engage aerial PTO with

park brake on, shift selector in N (neutral), and aerial master circuit on."

4-115