Circuit Description
This symptom chart will aid in diagnosing a failed power take-off (PTO) indicator. This diagnostic assumes that the PTO solenoid is functional and only the indicator is failing to come on. When the ignition switch is in RUN, voltage should be present on the Ignition 3 Voltage circuit. When the PTO switch is turned to ON, the LED will illuminate. The indicator has its own ground circuit. The LED and PTO solenoid have different ground circuits. Therefore, the LED may be illuminated when the PTO solenoid is disengaged.
Test Description
The number below refers to the step number on the diagnostic table.
Step | Action | Yes | No |
|---|---|---|---|
Schematic Reference: Power Take-Off (PTO) Schematics | |||
1 | Did you perform the Diagnostic System Check - Vehicle? | Go to Step 2 | |
2 | Did you review the Power Take-Off Description and Operation and perform the necessary inspections? | Go to Step 3 | |
3 | Verify the fault is present. Does the system operate normally? | Go to Testing for Intermittent Conditions and Poor Connections | Go to Step 4 |
4 | Does the PTO solenoid engage? | Go to Step 5 | |
Does the indicator come on? | Go to Step 6 | Go to Step 7 | |
6 | Repair the open or high resistance in both ground circuits 8 and 1850. Refer to Wiring Repairs. Did you complete the repair? | Go to Step 8 | -- |
7 | Replace the PTO switch. Refer to Power Take-Off Switch Replacement. Did you complete the replacement? | Go to Step 8 | -- |
8 | Test drive the vehicle and operate the PTO system as described in the supporting test. Does the symptom occur? | Go to Step 4 | System OK |
