Back again for some more help with our 2014 intermittent dash cluster. Over the past 2 years, GM has replaced a wire harness, instrument cluster, ignition switch and three relays in the fuse panel under the hood. I decided they just don't have a clue despite seeing the panel go dead while their diagnostic equipment was attached. (The only error they captured indicated a "loss of communications".)
They now think it is a faulty ground. Rather than pay them to chase that, I'm thinking I can do the same. I see the ground under the hood near the battery but, are there other grounding location under the dash? I'm thinking the body control module is somehow involved in this and perhaps it is its ground that is at the root of this issue.

Thanks,
Gary

 

The upfitter manual has beautiful drawings of all the ground locations, harness routing etc. Have a look.

https://www.gmupfitter.com/pages/body-builder-manuals

 

Just downloaded that...quite a bit of information! This will keep me busy this afternoon. Thanks for the link.
Gary