I have a 2003 Chevy 2500HD with a LB7 in it. The whole gauge will not turn on with the key cycle. After u drive a couple of miles they turn on and sometimes they never turn on. Is there a module that controls the gauge cluster? and is so where is it located? Any suggestions would be greatly appreated!!!
Thanks KY Diesel Boy

Just curious....how old are your batteries? Old batteries will cause that condition, as the cluster needs to see a certain voltage to "wake up".

If the batteries are recent, Id look at your chassis grounds (under the drivers door on the front cab mount).

Sounds like the common cluster issue. The time I had on a 2003 Avalanche 2500 was the same. I replaced the battery and not had the problem after that. The different modules can be voltage sensitive. There is a possible free fix from GM but i do not know the years related or requirements. Might search the site for that. or check with a dealer. Most of the gauge cluster is feed from the ECM and over the serial databus.

Brian

Moved to Electrical for further diagnosis.

The Batteries are about a year old. and i'll check that chassis ground. Thank you for your help

I had a wire that had some insulation missing that was for the data bus i soldered and put heat strink on it. Didn't help the sitution any at all. Thanks again for the input