2000 Tahoe service 4WD light

[rockola1971]

Yup - it’s been awhile, but I followed this suggestion a few years ago. I found the black ground wire in the harness (drivers side, near manifold) and created another ground off of this wire (splice into but leaving original in tact), attaching this ‘new‘ ground directly to a grounding point on the fire wall. Helped to super-ground the system

Super Ground? Doesnt exactly work that way since you have a main ground wire that ALL chassis mounted ground wires will attach to. What you can create is a ground loop condition by adding non factory grounding points and that is not a good thing.

 

[Rolexus]

You may be correct. However, when I had a problem with the grounding of the 4WD system a few yrs ago, and I had cleaned and reconnected all obvious grounds. Then someone on this forum suggested this process; I completed the suggestion. The results were a full functioning of the selector switch (AWD, 2WD, 4WH Hi, and 4WD Low) and still the case, almost 3yrs later.

So that ground wire (on the above mentioned harness) which I reconnected to the firewall must have been deteriorated beyond that point, because this fix worked.

 

[InterceptorF]

SUCCESS for me was the ground wire under cylinder 1 from the battery was sloppy/loose. Of course it was the last one I checked - doh....