How JustAnswer Works:
  • Ask an Expert
    Experts are full of valuable knowledge and are ready to help with any question. Credentials confirmed by a Fortune 500 verification firm.
  • Get a Professional Answer
    Via email, text message, or notification as you wait on our site.
    Ask follow up questions if you need to.
  • 100% Satisfaction Guarantee
    Rate the answer you receive.
Ask Jake Cheek Your Own Question
Jake Cheek
Jake Cheek,
Category: Chevy
Satisfied Customers: 24
Experience:  Automotive Technician at Hendrick Chevrolet
Type Your Chevy Question Here...
Jake Cheek is online now
A new question is answered every 9 seconds

I have a 2000 Cheverolet k3500 that is blowing out the 20

Customer Question

I have a 2000 Cheverolet k3500 that is blowing out the 20 amp fuse for the 4wheel drive when the manual*****is engaged. I have disconnected the front axle actuator, it still blows the fuse. I have inspected the wiring and have not found any damaged wires. The transfer switch checks good. The wiring to the relay on the firewall looks undamaged. Any ideas. Thanks jh
JA: When it comes to this particular vehicle, have flat tires been a problem in the past?
Customer: No
JA: What is the model of your '00 Chevy?
Customer: K3500 pickup
JA: Are you fixing your vehicle yourself? What have you tried so far?
Customer: Yes. Read first responce
JA: Anything else you want the mechanic to know before I connect you?
Customer: I can't thing of anything
Submitted: 8 months ago.
Category: Chevy
Expert:  Jake Cheek replied 8 months ago.

Hi my name is***** to JustAnswer.

Sounds like the encoder motor for the transfercase is shorted internally. Let me write up a few tests for you.

Expert:  Jake Cheek replied 8 months ago.

Here is the encoder motor connector and circuits. I would unplug the encoder, replace the fuse and check for good ground at terminal A on the connector side. If that is good check for 8v at E. Then at the motor, check to see if E is grounded. If it is you have a bad encoder motor.

Here is a description of the Encoder motor on the transfer case.

The TCCM operates the motor/encoder in one direction by energizing one relay while the second relay is de–energized. The TCCM operates the motor in the reverse direction by energizing the second relay while the first relay is de–energized. The encoder part of the motor/encoder sends shift positioning signals to the TCCM.

The motor/encoder converts a shaft position, representing a mode of range selection, into electrical signals for use by the TCCM. By interpreting the four channels (P, A, B, C) of the encoder, the transfer case control module can detect what position the transfer case is in 2HI, 4HI, 4LO, or in transition between any of the two.

The four hall effect sensors of the motor/encoder are used for channels (A, B, C, and P). These sensors provide a path to ground when a magnet passes over them. A rotating magnetic ring causes the hall effect sensors voltage to drop from 5 to 0 volts. The TCCM detects the voltage of all the channels and interprets the current transfer case shift position.




Encoder Signal Ground




Encoder Output - Channel A




Encoder Output - Channel C




Encoder Output - Channel B




Reference Voltage Input - 8 V




Encoder Output - Channel P

Customer: replied 8 months ago.
this is a manual floor shift, not a push button*****
Expert:  Jake Cheek replied 8 months ago.

Ah I see, much different indeed. Let me do some digging.

Expert:  Jake Cheek replied 8 months ago.

Is this an automatic or manual transmission? Gas or diesel?

Expert:  Jake Cheek replied 8 months ago.

For an automatic this is the only circuit besides a fuse block failure that could create a short. I would check this circuit first.