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Need help with new to me 2001 K3500 Dually- 4x4 wiring missing!

tgrisko
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tgrisko Enthusiast

tgrisko

Posted
Posted

Ok...  First off I just bought this truck with the LB7, 156K on the clock in pristine condition, ( at a GREAT price) so I thought the 4x4 issue was going to be an easy one since I have a 2004 Z71 and know it pretty good.  The PO didn't even know the 4wd wasn't working as he never used it and didn have the truck for very long, so I can't blame him ( he is like 80yrs old).

 

Here goes the story.....

( pic #1) 2001 K3500 dually with the LB7.... somewhere along its life, someone did a 03-07 front clip conversion on it.... its been a while for sure as all the paint matches and weathering is even...  all parts were painted prior to install as there is no sign of over-spray anywhwere.. not even bolt heads on the fenders.

 

( pic #2) I get the truck home... she runs perfect!  I went thru all the essentials the first week and made a 1000+ mile trip towing my 38' Raptor Toy Hauler at 65-70mph with zero issues on the 6th day of ownership.

 

Time to tackle the 4x4 issue:

 

The 4x4 switch is dead... no lights.  I pull the switch...  NOT CONNECTED!!!  can't find the connectors.  I dig deeper and I find one... but its different than the switch ( pic#3)  no other connector to be found

 

Keep digging....

( pic #4)  Follow t-case wiring up to side of under the hood fuse box....  NO CONNECTORS GOING THRU THE FIRE WALL connecting to the t-case harness!  WTF!?!

 

Continued on next post....

 

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tgrisko Enthusiast

tgrisko

Posted
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Posted (edited)

Digging deeper....

(pic# 1) Under the dash.... There should be 4 pigtails here...  2 for the 4x4 switch, 1 for the light module and 1 for the cab light...  ALSO,,,, NO TRANSFER CASE CONTROL MODULE FOUND!!!!  No pig tails that would even go to the TCCM!  I know the location is the same for my 04 Z71... its missing and no pig tails from the harness at all

 

Here is where it gets good...  digging deeper....

 

I follow the main harness thru the firewall under the dash to where the pig tails should be for the TCCM and I notice the tag on the main harness ( pic #2)  DATE STAMP 2003!?!

 

Now I am not above believing this truck is a hodge-podge of mixed parts at this point...  basically all the 4x4 drivetrain all is there with the exception of the correct main harness with t-case connections under the hood under the fuse box cover.. which would also contain the correct connections for the 4x4 switch in the dash and the Transfer Case Control Module ( which is missing )

 

So...  my question would be this...

 

The part number on the 2003 dated harness is this 15204375  with a barcode number of Z76384375.... I 'think' this is the wrong harness for this truck...

 

How can I find out which harness I need and does anybody have really good wiring diagrams as I can't find a SINGLE ONE I NEED!

 

Thanks in advance for all the help and knowledge....

 

 

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Edited by tgrisko
CamGTP Senior Enthusiast

CamGTP

Posted
Posted

I'm starting to think that really is a 2003 truck. The cluster is a 2003+ as well and that only works with a 2003+ interior/BCM harness.

 

What's the VIN number on the door and the dash say?

 

 

tgrisko Enthusiast

tgrisko

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I'm starting to think that really is a 2003 truck. The cluster is a 2003+ as well and that only works with a 2003+ interior/BCM harness.   What's the VIN number on the door and the dash say?

 

 

 

 

Thanks for responding ... the title and dash match....no door tag... its clean....i would love to verify this... if only just for getting the correct parts...i just want to get it all working correctly... 4x4 is all that doesn't work... everything else is cherry

 

What do you make of not having a TCCM and no.connections on the harness for it or the 4x4 switch? 92946cd91bef7b0677abd2d83d9b79ff.jpg Sent from my SM-G975U using Tapatalk

 

 

 

 

 

 

 

CamGTP Senior Enthusiast

CamGTP

Posted
Posted

Hmm, something still doesn't add up with the harness showing a 2003 time stamp. A cab swap is the only other thing that comes to mind.

 

This is what a 2000-2002 Duramax cluster looks like.

 

s-l1000.jpg

tgrisko Enthusiast

tgrisko

Posted
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Posted
Hmm, something still doesn't add up with the harness showing a 2003 time stamp. A cab swap is the only other thing that comes to mind.   This is what a 2000-2002 Duramax cluster looks like.  

s-l1000.jpg

 

 

 

My cluster looks different.. my redline starts at 3200 rpm... never even gets close to that when it's shifting and pedal on the floor. Most notable difference is the one you posted has a rectangle display in the upper left... mine has the rounded edges.  

 

A cab swap... hmm that could explain a few things... like if it came from 2wd model..no TCCM and pigtails from the main harness... you may be onto something

 

By the way... thanks alot for helping me out... gonne get it figured out one way or another

 

248306c4259ede3cf31ee88e10240a02.jpg 

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davester Senior Enthusiast

davester

Posted
Posted (edited)

Is the transfer case itself manual or electric?

The Message Center part was an option (but I don't know what trim levels or if it was on all diesels).

As for the wiring diagrams, I would suggest subscribing to the full-service manual at a site like alldatadiy.com .Unfortunately, If your truck is a hodge-podge of '01 and '03, you might need to subscribe to both years, as I think in '03 GM revamped their computer system and wiring, so probably will take a lot of comparing to figure out what's what...

 

Check if the VIN on the decal in the glovebox matches the vin you posted, that might also give you a clue if it's different.

You could also email the vin to [email protected] and request a build sheet for that vin.

 

Something else you could try, would be to use a more advanced code reader to get the vin out of the ecm, and see if it matches the truck's vin...

Edited by davester
tgrisko Enthusiast

tgrisko

Posted
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6 hours ago, davester said:

Is the transfer case itself manual or electric?

The Message Center part was an option (but I don't know what trim levels or if it was on all diesels).

As for the wiring diagrams, I would suggest subscribing to the full-service manual at a site like alldatadiy.com .Unfortunately, If your truck is a hodge-podge of '01 and '03, you might need to subscribe to both years, as I think in '03 GM revamped their computer system and wiring, so probably will take a lot of comparing to figure out what's what...

 

Check if the VIN on the decal in the glovebox matches the vin you posted, that might also give you a clue if it's different.

You could also email the vin to [email protected] and request a build sheet for that vin.

 

Something else you could try, would be to use a more advanced code reader to get the vin out of the ecm, and see if it matches the truck's vin...

T-case is push button...  I went under...  harnesses are all there from the t-case....  but stops at the fuse box under the hood.

 

Thanks for the suggestion on ALL DATA.... I may have to do that for sure.

 

So...  this is funny...  you mention decals for VIN DATA....   IT HAS NONE!!!!   Both the glove box and door jam are clear of any decals.  AS far as [email protected]...   I will give that a shot.

 

Do you know of any other locations I may find a VIN on the body anywhere?  I know back in the day you can verify in 2-3 places... not sure on these newer vehicles....  thanks!

 

My concern is this....  CamGTP suggested a possible cab swap was done....  I have NEVER done that so I don't know the answer to my question.... is it possible to install a dash and VIN plate from the the original 2001 into a 2003?   The VINTAG in the window looks to be unmolested in a way, shape or form.

tgrisko Enthusiast

tgrisko

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Posted (edited)

Pic of the VINTAG

 

5e8351cf9b4f4093aac9319d8c516029.jpg

 

Where else can I find a stamped VIN on the body?   Gotta get to the bottom of this... thanks for all your help guys... much appreciated!



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Edited by tgrisko
tgrisko Enthusiast

tgrisko

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Posted (edited)

Ok... I have been researching cab swaps... I found a video that somewhat gave me guidance on a few things...  There is a difference on the main dash harnesses from 2wd to 4wd....  not sure what could be original and whats  swapped over...  Looks like they used at least the dash from a 2003 ( possibly) since the main dash harness can be disconnected from the under-hood fuse box.  and pulled thru the firewall.  IF they did this and used a a donor from a 2wd vehicle... this explains why there is no TCCM or its connections.  I may be on the hunt for a dash... problem is... not sure which one I need to make this all work!  LOL!   Im thinking if I can find a 2001 4wd donor 4x4 truck, I could be in business.   I know that it was mentioned that the BCM may be different, but I watched a 2002-2004 cab swap and it wasn't an issue... I know 2003 was a change year, but not sure how much of the wiring changed except for the dash.

 

Im gonna pull some part numbers of different components on the dash that may give me some guidance on what I may need to make this work.

 

insight from the group is always welcome and appreciated... and THANKS TO CamGTP and Davester for all the help thus far.

Edited by tgrisko
tgrisko Enthusiast

tgrisko

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Posted

Cluster p/n is 15114652---- definitely a 2003-2007 cluster67b1c685f8958de280221cf2cafd1f08.jpg

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tgrisko Enthusiast

tgrisko

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Not even sure if I have the correct 4x4 switch now... no part number on itc3244931b8fedbd2e0eae91cd7458575.jpg

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tgrisko Enthusiast

tgrisko

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OK... now Im really confused... here is the build sheet.  Can some one decipher this...  yes its a K3500 LS  4WD Dually with the LB7 Duramax and Allison 5 speed auto.   Explain why the LS option calls for power mirrors, PDL etc!?!?  I have NONE of this... LOL!!   Are the options  just that... OPTIONS that I could have or is this what the truck was supposedly equipped with when built?

 

This just keeps getting better by the minute.  Where does it say DUALLY or DRW...  did I miss it?

( PDF of build sheet also attached)

 

buildsheet.JPG

1GCJK39121F121235 - BUILD SHEET.PDF

Edited by tgrisko
tgrisko Enthusiast

tgrisko

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Let's add to the mayhem.. camGTP... YOU WERE RIGHT! BCM is for 03-07...

This is gonna get fun!!!6d35501406145219774aa311573ee102.jpg

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