Just recently took possession of a 2003 Chevy Suburban 1500 and was made aware of the 4x4 selector issue. In my case it was typically starting up in the Auto 4WD spot or occasionally in the N spot and then not changing to the 2H when selected (but still driveable). Other times it would start off on ignition in different settings. Typically could push a button to correct or the next time it would start off in correct 2H spot.

I did my research and bought a replacement switch, installed it and it worked well for the next week with maybe a half dozen on/off cycles.

So i dig deeper and found the grounding issue and removed the ground wires and cleaned the wires and dremeled the metal plate and the overspray/crud.

The switch started working perfectly for the next 6-8 start restarts again including shifting through various iterations of 4WD.

Then the same random starting position started up again. I’ve watched almost all the YouTube videos out there on it and one of them comes to my mind when the mechanic states your going to have to replace your switch after fixing the ground. He didn’t mention why but that’s the core of my question. If it was the ground and I replaced the switch before fixing the ground did I kill the “new” switch and need to replace it now?

Thanks for any advice!

 

Welcome to the forum from Oregon.

Check this out: https://www.fixmyoldride.com/Chevrol...pos=3&at_tot=4

Plus, check out some you tube videos about the encoder.

 

Thanks for that info! Hadn’t considered perhaps the battery ground as I haven’t been seeing any other electrical weirdness.

 

This is a thread about a popular fix for these weird intermittent electrical problems. It works.

https://www.tahoeyukonforum.com/thre...stions.111196/

Another link that is in detail: https://www.gmfullsize.com/threads/h...d%20alternator.

Lots of info out there: https://jlaudio.zendesk.com/hc/en-us...Wiring-Upgrade

Just google "GM Big 3 Upgrade" and lots of info comes up.