guages stop, no communication, plz help

[Skylardog123]

so i have an 04 silverado 5.3, here lately my guages will just randomly all drop to 0, low fuel light will come on, the line under the prndl indicator dissapears, and also voltage guage has been reading low, like 9.5-10.5v, whenever this occurs, i lose communication with pcm, my tuner was trying to tune my truck and halfway through the read, the guages died, and he lost communication with hptuners, so we had to bench tune it, the truck still starts and drives fine, i have an aftermarket radio with pac interface, but i pulled the radio fuse and it still does it, pulled radio harness and it still does it, its random though, not exactly like a loose wire because i can just be sitting absolutely still and the guages sometimes still shutoff, sometimes happens while im driving, any ideas what this could be? before the loss of communication brings me more issues, i was personally thinking maybe a shorted out BCM considering the canbus system is connected directly to bcm, or any other modules connected to class 2 serial data, someone please help with this

[Sharpz]

inspect your cluster gauge assembly if at all possible try plugging another one in to see if it gives you any issues.  you can also make sure all of the grounds you can find are secure and have a good connection. If the first two check out, then check that your bcm doesnt have any solder issues.  You can search bcm solder issues to see what I am talking about.  If the bcm doesnt seem to have any solder issues, I would guess that you have a wire problem.  When it heats up it starts giving fits, but nothing when its cold.  I hope this helps you. 

Edited January 22, 2021 by Sharpz

[Ian Mills]

So the voltage gauge doesn't drop all the way to the bottom but it reads as low as 9.5v? Sounds like that might be the ticket. If that voltage reading is accurate, it could explain the loss of communication with the truck.