Table 4-2. Unit Troubleshooting - Continued
TEST OR INSPECTION
ELECTRICAL SYSTEM - HI-IDLE CIRCUITS - Continued
RUN/LOCK LEVER ON AERIAL PANEL WILL NOT ENGAGE HIGH IDLE WITH PARK BRAKE
ON, SHIFT SELECTOR IN NEUTRAL, AND AERIAL MASTER SWITCH ON
(Refer to Electrical Wiring Diagrams, Appendix H, Sheet 9 of 16.)
Step 1. Attempt to engage high idle with cab switch.
If cab switch engages high idle, go to step 2.
If cab switch does not engage high idle, refer to "cab switch will not engage high idle with
parking brake on and transmission selector in N (neutral)."
Step 2. Attempt to engage high idle with rear panel switch.
If rear panel switch engages high idle, go to step 3.
If rear panel switch does not engage high idle, refer to "rear switch will not engage high idle
with parking brake on and transmission selector in N (neutral)."
Step 3. Check limit switch at RUN/LOCK for proper operation.
Replace limit switch (see para 4-185).
Step 4. Check "on" timer for proper operation (a +12V signal applied to wire 1207 should produce
a +12V signal on wire 1133 for 1/2 second).
Replace timer (see para 4-9.4).
Step 5. Check for +12V at circuit breaker #5 on the aerial master buss.
Replace breaker (see para 4-99).
Step 6. Check wiring for continuity.
Replace wire (see para 4-9.4).