2000 gmc 1500 4x4 push button flickers

[classicxl]

My 2000 Gmc sierra 1500 that had a complete frame up rebuild using a 2005 complete rolling chassis as well a low mileage 05 5.3 vortec and the 2005 main wiring harness front to back .problem is the push button 4x4 doesn’t light up but if i pull the 4x4 fuse in the cab and i just barely put the fuse back and wiggle it up and down i get some clicking noise and for a second the push button flickers . is this a bad ground or punched wire causing my problem before i ripped the truck apart because of a rotted frame for the rebuild the 4x4 worked but the 2000 wiring harness was completely full of water and had to be changed . By the way the front drive shaft is removed as well as encoder motor because it was stuck in 4x4 

Edited January 24, 2022 by classicxl

[Sharpz]

it sounds like you have many issues ongoing.  Making sure all of your grounds are hooked, is the first thing.  I am not sure of the compatibility of your bcm and ecm with a 2000, vs 2005.  It may be a matter of just taking it to your local gm dealership and getting things reprogrammed.  I am not sure what frame up means, but if that means you got a frame, and a cab........... from a 2005, then what exactly did you take from the 2000?

[richard wysong]

the clicking would be a relay and without an encoder motor no light may be normal

[richard wysong]

if you don't have the encoder why do you need the light to do anything

[classicxl]

Frame up means everything on the frame was restored to like new condition . story is i bought a 2000 gmc looked mint then discovered the frame was bad behind fuel tank. 

 

My friend who sells gm trucks found a very low mileage 2005 truck that it’s older owner had rolled his tuck into a ditch but everything else was in like new condition. We took my 2000 cab and box and put it on the 2005 frame . used the 2005 wiring harness because mine was full of water and put in a good used computer and it was reflashed 

 

 

push button switch when i first bought  the truck from the dealer ,  each 4x4 selection button did  light up and worked  now nothing unless i wiggle the fuse it flickers for a second