Help Needed four wheel drive

Discussion in 'Site Feedback & Support' started by phipps, Jan 22, 2015.

  1. phipps

    phipps SDD Junior Member

    Messages:
    2
    Likes Received:
    0
    Joined:
    Jan 22, 2015
    Location:
    grand blanc ,mi
    I have a 2003 xlt 7.3 and the 4x4 switch dash seems to be not working fuses are good ,defrost and all is working fine looking for help on were to start?
     
  2. dboyw

    dboyw Full Access Member

    Messages:
    358
    Likes Received:
    0
    Joined:
    Aug 30, 2005
    Location:
    Lancaster, PA
    With a switch on the dash, I will guess you have the auto lock hubs. If so, most likely is you have a vacuum leak at the hubs, common problem. Quick check is to manually turn the hubs to lock. The axle is live now but not in 4x4. Go drive and switch to 4x4. This should still engage the transfer case. Do you have 4x4? If so, start looking for the vacuum leak. The hoses near the hubs are a likely culprit.
     
  3. phipps

    phipps SDD Junior Member

    Messages:
    2
    Likes Received:
    0
    Joined:
    Jan 22, 2015
    Location:
    grand blanc ,mi
    I tried locking manual hubs still nothing, when I turn switch to 4x4 the dash light dose not come on,i pulled dash out by switch and there is no power going to switch,fuses are good,i put new relay in under hood by airbox , vacuum pump is working,no problems with switching hvac?.. the light on dash works for a short time when starting , and there in nothing going on at transfer case
     
    Last edited: Jan 22, 2015
  4. DaveBen

    DaveBen SDD Senior Member

    Age:
    72
    Messages:
    9,586
    Likes Received:
    75
    Joined:
    May 31, 2005
    Location:
    Ukiah, California
    There is a shift motor in the transfer case that can go bad. If the motor is shot, no four wheel drive. I do not know how to test the motor other than putting +12v and seeing if it engages the gear for four wheel drive. You will hear it shift.

    Dave
     
  5. JLDickmon

    JLDickmon ursus combibo

    Messages:
    4,171
    Likes Received:
    12
    Joined:
    Jun 22, 2006
    Location:
    49041
    there are two relays under the hood, at or near the main fuseblock that control the shift motor..
     
  6. RandyH

    RandyH Full Access Member

    Messages:
    262
    Likes Received:
    5
    Joined:
    Feb 24, 2008
    Location:
    Western Colorado

Share This Page