funtwodrv

New Member... All the gauges, digital readout and turn signals on the cluster will intermittently shut down. This seems to happen after about two hours of normal operation. This lasts just a few seconds and then everything is back to normal for a few minutes. The engine and trans work normally during these periods. The dealer has been working on this on and off for the past 18 months.
So far, the only real repair is the dealer replaced the instrument cluster. That seemed to solve the issue for about four hours and then it started acting up as described. They are at a stand still now. They have opened two technical support cases with GM TAC. One resulted in them determining the cluster needed replacing the other was to remove the after market radio.
I'm beginning to think it is a flaky body control module but that's just a guess. Any thoughts or experience on which way to go next?

Gary

StanVan

No ideas here, but the radio wouldn't have anything to do with it. They're just guessing at that. The only way the radio could affect it is if the installer ignored the radio harness, and somehow tied into the cluster harness, which would be difficult to do, at best.

Artie1

Bad electrical contact somewhere. This could use some creativity to find, that is something dealers generally lack. Typical dealer's approach of throwing new parts until it's fixed, isn't too productive here. One needs to open diagrams and check for ground and 12V supply and find out what is causing that. I would hook up 3 multimeters spliced to the cluster connector (one to ground, one to constant 12V and one to ignition switched 12V) and drive around until this condition happens and then perhaps will be able to see.

StanVan

That was my thought as well, but I am not experienced in these systems. I installed stereo and radio equipment back when ABS was just coming about. My other thought is that it is conceivable that there is a thermal issue with a component on a circuit board, that fails when it overheats.

And I'm with you on that "creativity" thing, Artie. But I wouldn't limit that to dealers. Generally speaking, people can be quick to jump to a conclusion in any circumstance.

funtwodrv

Thanks for the replies. This chassis is attached to a Class C RV. We are leaving in a few days so, it will be a week or two before I can try Artie's suggestions. I suspect it may be a ground as yesterday I noticed the digital display changed brightness a split second before the gauges dropped out. I also noticed it changing brightness during the times the flashers/turn signals were freezing. Another tidbit I noticed yesterday, the emergency flashers would freeze with the engine running but would not freeze when the ignition was turned off.
Another bit of info, I have had a code reader plugged in during these episodes and it doesn't appear to be effected during these dash outages...no codes either. The dealer also noted no codes are being stored. Which makes me lean towards a voltage or ground issue. However, a "special" scan program that TAC ran indicated a faulty instrument cluster... which was replaced. I suspect either a bad connector, faulty workmanship(which is very possible based on their track record) or a supply line or ground wire.
I will update this in a few weeks once we get settled in a location I can tear into the dash and test the 12v circuits and grounds..
Thanks again,
Gary