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Automatic Differential Disconnect Power

Discussion in '1st Gen. Tacomas (1995-2004)' started by taconator911, Feb 18, 2015.

  1. Feb 18, 2015 at 3:48 AM
    #1
    taconator911

    taconator911 [OP] Member

    Joined:
    Oct 6, 2013
    Member:
    #113959
    Messages:
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    First Name:
    Mike
    Labrador
    Vehicle:
    4x4 ext cab V6
    aisin hubs, adj coilover, uniball UCA's, aftermarket clutch HD, scan guage 2, aftermarket muffler, 285/75/R16 BFG, add-a-leaf, dbl dimm touch screen stereo, diff drop 1"
    Hey guys and gals, I am having a specific problem with my ADD. I have searched many of threads that either didn't help me with my specific problem or lead to dead links so I am hoping you can help me out. So here goes,

    I have 2002 SR5 V6 4x4 Tacoma with manual shift transfer case and I am having trouble with the electric ADD (not vacuum) not engaging into 4x4. When I put into 4H the front driveshaft locks in and spins but the power doesn't get delivered to wheels. When I lock in hubs (I swapped out auto hubs for manual hubs) the CV shafts spin with tire by hand when jacked up but one tire does not move the other indicating that in front end is where my trouble is. I get no light on my dash when switched into 4H to indicate 4x4. So I then jumped the pins (1 blue and 5 red) on the actuator to test its functionality and I could hear it engaging and unegaging, so I engaged it and started up my truck, the light on dash came on for a second and it unegaged by ifself and light went out.

    Therefore I believe I am dealing with an electrical issue, maybe a relay or something but I cannot seem to find much info on this for my year and model ADD. I have a Haynes manual but it seem to only deal with vacuum operated version. Can someone help shed some light on this problem and any locations of the various electrical sources for this system?

    Thanks any help appreciated...
     
  2. Feb 18, 2015 at 11:01 AM
    #2
    taconator911

    taconator911 [OP] Member

    Joined:
    Oct 6, 2013
    Member:
    #113959
    Messages:
    11
    Gender:
    Male
    First Name:
    Mike
    Labrador
    Vehicle:
    4x4 ext cab V6
    aisin hubs, adj coilover, uniball UCA's, aftermarket clutch HD, scan guage 2, aftermarket muffler, 285/75/R16 BFG, add-a-leaf, dbl dimm touch screen stereo, diff drop 1"
    Anybody? If I have to read check your vacuum lines one more time I'm gonna flip....no vacuum lines just a breather and electrical connector. The actuator works, it's just not being supplied the voltage. I need to know where to find relays, fuses, shifter switch connection, etc. I cannot trace wires very easily because it just goes to engine bay into main wiring harness. Somebody please have some info?
     
  3. Feb 18, 2015 at 12:44 PM
    #3
    slander

    slander Honorary Crawl Boi

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    Yea its all electric down there. Its going to be hard to trouble shoot without the wiring diagram, however, the sensors are on the right side of the tcase and run to a harness that's on a bracket on top of the trans. You should be able to access those from under the truck, or take your console out and go down from the top. I had a problem with similar to this after i ripped the connector apart after i forgot to disconnect the harness and dropped the tcase. I would start from the transfer case and work your way forward checking the connections, i doubt its an issue at the regulator.
     
  4. Feb 18, 2015 at 1:15 PM
    #4
    taconator911

    taconator911 [OP] Member

    Joined:
    Oct 6, 2013
    Member:
    #113959
    Messages:
    11
    Gender:
    Male
    First Name:
    Mike
    Labrador
    Vehicle:
    4x4 ext cab V6
    aisin hubs, adj coilover, uniball UCA's, aftermarket clutch HD, scan guage 2, aftermarket muffler, 285/75/R16 BFG, add-a-leaf, dbl dimm touch screen stereo, diff drop 1"
    Hi I did check those connections to make sure they were properly seated, maybe I will touch up with dielectric grease and test for proper values with a volt/ohm meter. If I can find some values and procedures. I maybe missing one though hard to get up around top of transmission/ transfercase from bottom. I had cover for shifters off but couldn't see much from there. For now I have some pics can you tell me what it is for? It is a relay I got from behind my glove box up in right corner, for some reason with the various things I've read I believe this maybe the ADD relay. In the glovebox pics the relay is removed but you can vaguely see the white connector it plugs into way in the back there.

    DSC_0026.jpg
    DSC_0023.jpg
    DSC_0024.jpg
     
  5. Feb 18, 2015 at 1:29 PM
    #5
    slander

    slander Honorary Crawl Boi

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    02 Tacoma, fixed with curse words.
    Hmm i have no idea, ive never had to dive into the 4wd computer/relay. The connector is on top of the trans, between the shifter and the firewall on the pax side. Its a PITA to get to.
     
  6. Feb 18, 2015 at 1:34 PM
    #6
    taconator911

    taconator911 [OP] Member

    Joined:
    Oct 6, 2013
    Member:
    #113959
    Messages:
    11
    Gender:
    Male
    First Name:
    Mike
    Labrador
    Vehicle:
    4x4 ext cab V6
    aisin hubs, adj coilover, uniball UCA's, aftermarket clutch HD, scan guage 2, aftermarket muffler, 285/75/R16 BFG, add-a-leaf, dbl dimm touch screen stereo, diff drop 1"
    OK thanks I will check that, thanks for info, I don't think I checked that one sounds like fun.
     
  7. Feb 18, 2015 at 4:21 PM
    #7
    taconator911

    taconator911 [OP] Member

    Joined:
    Oct 6, 2013
    Member:
    #113959
    Messages:
    11
    Gender:
    Male
    First Name:
    Mike
    Labrador
    Vehicle:
    4x4 ext cab V6
    aisin hubs, adj coilover, uniball UCA's, aftermarket clutch HD, scan guage 2, aftermarket muffler, 285/75/R16 BFG, add-a-leaf, dbl dimm touch screen stereo, diff drop 1"
    Ha got it fixed. First off let me say that that relay is for headlights oops lol. When I went out looking underneith the truck at all the connectors again there was one that went to rear of transfercase near driveshaft which i read somewhere that it was a speed sensor (although I am used to them being at the flywheel) which I assumed I had hooked up correctly because my speedo was working. Well there is two of the same type connectors that the harness for this sensor can plug into and I of course had plugged into the wrong one. I mustve done this the summer when I changed my clutch and I havent had a need for my 4x4 since because my suspension is shot and ive been avoiding the trails. So I switched connectors and now feel like and idiot haha let the flaming begin.....thanks for the help guys.

    On another but similar note, what would cause 4H to kick out of gear sometimes back into 2H on its own when taking a turn, it's not really binding much as im not on dry pavement but icy roads?
     

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