On a 1992 Chevrolet Silverado 4x4 It has manual shift transfer case but automatic hubs. The front end an acctuator motor it is not getting fire.what sends this fire to actuator?

The signal to fire the actuator motor for the automatic locking hubs on your 1992 Chevy Silverado 4x4 comes from the transfer case shift motor. More specifically, it's controlled indirectly through the transfer case's internal circuitry which is activated when you shift the transfer case into 4WD.

Here's the breakdown:

1. Transfer Case Shift Lever: When you shift the transfer case lever to 4HI or 4LO, this activates a motor *inside* the transfer case.

2. Transfer Case Shift Motor: This motor moves a linkage or gear internally.

3. Electrical Switch/Sensor (within the transfer case): This switch, often integrated into the transfer case's internal mechanism, detects the 4WD engaged position. This switch then sends the power signal.

4. Actuator Motor (Hubs): The power signal from the internal switch energizes the actuator motor in your front wheel hubs, locking them for 4-wheel drive operation.

Troubleshooting Steps:

Since the actuator motor isn't receiving power, the problem is likely *before* the motor itself. Here's a logical order to investigate:

1. Transfer Case Shift Lever & Linkage: Ensure the transfer case lever is moving freely and is fully engaging in 4HI or 4LO. Check the linkage for any damage or binding. A problem here might prevent the internal motor from operating properly.

2. Transfer Case Shift Motor: Test the motor itself (if accessible) for functionality. A multimeter can test its voltage and continuity. This requires disconnecting the motor, which might involve some disassembly. A faulty transfer case shift motor is a common cause.

3. Wiring from Transfer Case to Hubs: Inspect the wiring harness running from the transfer case to the front hubs for any breaks, shorts, corrosion, or loose connections. A simple visual inspection is needed, but you might need to trace the wires.

4. Switch/Sensor (within the transfer case): This is the most difficult component to test without specialized tools and some mechanical knowledge. If the other steps reveal nothing, the internal switch might be faulty. This usually requires transfer case removal or at least partial disassembly.

5. Fuse or Relay (unlikely): Though less common for the actuator motor itself, check your owner's manual for any fuses or relays related to 4WD or the transfer case.

Important Note: Working on the transfer case and its associated components requires mechanical aptitude. If you're not comfortable working with automotive electrical systems and mechanical components, it's best to take your truck to a qualified mechanic. Improper repair can lead to more significant damage.