ac, turn signals, speedometer’s gouges stop working for about 20 seconds then comes back on. All this happens while Im driving.
That might be the signs of a BCM starting to fail.
Drive the vehicle and see if there are any other electrical systems that start acting erratic.
You may need a new instrument cluster or some computer module (e.g. the above post), but first ask your shop to check if the problem is just the instrument panel is loosing its computer buss connection to the rest of the system. There have been a few tsbs and customer interest bulletins regarding the instruments, but I don’t see anything that matches your particular symptoms. That makes me think it is something simple, like a loose buss connector. Has anyone been doing work on this vehicle recently, especially in the under-dash area?