2005 2500HD 6.0L dash issues

12dbsinad · February 12, 2023

Recently my 2005 2500HD 6.0L has had it's dash going crazy. Randomly, the ABS, airbag and brake lights will illuminate together with the ding chime. It sometimes accompanies the fuel gauge, oil pressure, and volt gauge going to zero and the battery light will come on. Sometimes the lights will quickly flash, other times they will stay on until I get to my destination. Seems to be worse during cold weather (below 20F). Trying to troubleshoot this. I've read it could be anything from a ground issue to a bad BCM or cluster. Anyone run into anything similar or have any tips/tricks?

Edited February 12, 2023 by 12dbsinad

David89GMC · February 13, 2023

Haven't seen this before, but be sure to start with the grounds. Make sure they're perfect before proceeding onto the next possible cause.

davester · February 13, 2023

You might start with the grounds located on the wing off the frame, right below the driver's door. Disconnect and clean both the frame, bolts and connetors, then reattach.

Grubbworm · February 13, 2023

I would start with the fuses, check all of them.

I would also check ALL of the relays, with a relay tester. I just dealt with a similar issue with my wife's car. Turns out it was a relay going to an option that was not available on her model car. The relay for the "Bose Speaker/Woofer" was the culprit. I had a U0101 Code, Not communicating with TCM. As luck would have it the CAN (Controller Area Network) also runs through this circuit. Replaced relay and issue fixed. This was not on a GM vehicle, but the principle remains the same.

P.S. I got my Relay Tester off Amazon for about $12.

64BAwagon · February 13, 2023

Like the above post states, start with that ground lug. If that doesnt resolve it start looking at battery cables and connections. from there pull the underhood electrical center up and inspect the bottom of it for rodent damage. (remove the 4 screws and pull the diagonal brace, release the tabs on the cover and lift it off and then the panel can be released and flipped up to expose the bottom)

It's Tim · February 13, 2023

Start with a voltage drop test on the battery cables.

12dbsinad · February 13, 2023

Thank you all for the advise/help. I read another thread (not on this site) about a similar issue with a same vintage Tahoe having dash issues. Apparently there is a ground that affects the dash under the hood against the firewall that is a culprit of corrosion issues at the terminal, wire can still look attached but a slight tug and the wire pulled out of the terminal. Not sure if these trucks have that same ground but I will check that as well. Will also check relay/fuses. Drove the truck to and from work and to a appointment and never did it once but was fairly warm today (35-40f). My goal is to get it to do it, drive it in my shop and move ground bolts to see if it clears that way I have some sort of confirmation and not guessing. Again, thanks for the help and I will report back on updates so this thread can be as useful as possible.

Formulabruce · February 13, 2023

16 hours ago, davester said:

You might start with the grounds located on the wing off the frame, right below the driver's door. Disconnect and clean both the frame, bolts and connetors, then reattach.

Simplest first.. Do these grounds, and coat them with grease after.