Gauges, radio, and obd port not working.

[Carter Kelbert]

I am stumped. 
New to this forum so I am hoping I’m posting this in the right area, but desperately needing help on my 2004 Chevrolet Silverado 2500HD 6.0L 

 

So I went on a camping trip and while I was off roading, my gauges stopped working. The speedometer and my revs still work. But it doesn’t underline the gear I am in and all other gauges are dead. Doesn’t keep track of my kms as well and when I went to plug my obd reader in, it doesn’t work anymore too. It did this a few times before it completely stopped working. my radio completely died too. It started to reset itself when my gauges were acting up and died around the same time as when the gauges completely died. 
I hope this is making sense, but I’m at a lost and idk what to do. 
I’ve checked a few fuses that I think would cause it but nothing. 

I know the gauges are a common problem with the truck but why is nothing else working? Coincidence ? I’m thinking of replacing the ECU / ECM, maybe it got fried while off roading (didn’t go through that much water). No chewed up wires either. 
 

If anyone has a list I can go down of what to check, that would be amazing. 
thanks 

[richard wysong]

Check ALL fuses, a test light makes it quick and easy, under the hood and in the cabin, if that's ok check the underhood fuse box for corrosion, you may have to remove and clean the fuse connections

[mjm-1957]

Check the ignition switch.

[richard wysong]

ignition switch would not affect  power to the obd port,

[Carter Kelbert]

Could it just be me getting unlucky and a mix of different things happening? 
I’ll do a full run down of all fuses after work, I’m hoping it’s as simple as that. 

[richard wysong]

I believe the obd is powered by the lighter fuse . There have been a few posts of similar symptoms but nothing definite on the cause or solution other than the bad connections in the power distribution box under the hood and bad grounds affecting the bcm. Your symptoms are mild compared to most that disable the truck

[Carter Kelbert]

Hoping to take the truck off road.. so I hope my truck doesn’t get disabled  

I checked and re did some grounds that are attached to the frame underneath the drivers side, any other grounds I should check for and clean up? 
Yeah I haven’t found anyone who has posted a definite solution yet. The character of an old Chevy I guess 

[Carter Kelbert]

Well checked all fuses, everything appears to be working as should be. Stumped for now so if anyone has anything else I should check, it’d be greatly appreciated. 

[JBChance]

Posting on this because I had a similar issue. On the off chance you are watching this or also if someone is battling the same (thats how  ended up here), I wanted to post what I found out. I have a 2017 Silverado 3500HD, 6.0L gas.

 

My issue was caused by a short in the harness. Specifically for me, it was the trailer plug wiring. Because my truck is a salt truck, there is always chance for extra corrosion and so forth. The plug was put in aftermarket and the splices became compromised. The power circuit to the plug was shorting through and, I believe now, into the truck ground. You would think that would blow the fuse, but it did not. My truck would not go into reverse or shift, no tach/ speedo, and the OBD2 port was dead or couldn't communicate. In addition, weird goings on like the blower fan/ climate control would stay on with the truck off (and other things). 

 

When the episode occurred, the service trailer brake system warning went off directly prior, so I was lucky and started at the plug and discovered the short. From what I understand now, this scrambled the BCM/ ECM and created havoc. Once I corrected the short, nothing changed, until I reset the ECM by disconnecting the battery and letting the truck sit. I reconnected (ECM reset), and the truck operated normally. I did get the put the drivers window down and up promt on the info display indicating a reset.

 

Sorry for the long post, but I know I was stumped for a day, so, if this could help someone, so be it.

 

Cheers!