Minor inconsistencies in the electronics, curious to hear opinions

[Onecook223]

I recently purchase a 2011 Buick Lucerne and it runs and drives great with no issues. Considering my previous car had manual windows, locks, and a non functioning AC it is an upgrade to say the least. Recently I have noticed that the automatic lighting on the dash and buttons cannot be adjusted by the corresponding gauge until at random times when the lights decide to switch to a more dim but now controllable option. I have also noticed minor things like a slight fluctuation in the rpm gauge that especially fluctuates when engaging things like the AC condenser. I was curious to know what some other Buick owners think of this. I’m assuming it is a minor thing with the wiring or maybe something related to my battery / alternator? I am not knowledgeable when it comes to fixing cars but would love to learn more and continue down that path of being comfortable tinkering with my own vehicles. Thanks!

 

[2007LucerneCXL]

Not sure what is being asked as there isn't a gauge for automatic lighting. The control functions are on the headlight switch and it is a On of Off, the dash brightness is controlled by the smaller button next to the headlight switch. The sensor for this function is in the middle of the dashboard by the bottom of the windshield, if dirty or blocked may be something to check. See the owners manual for additional information.

Slight fluctuations in RPM's when the AC compressor engages when in idle is normal, again the question isn't clear on what other items may or may not be a issue.

Finding a reliable shop to inspect your vehicle is the best route as internet forums are best guessing based on details given.

 

[WalmartTech21]

the fluctuations in RPM when engaging the AC is completely normal as 2007LucerneCXL said, the PCM is compensating for the increased load on the engine from the AC Compressor by raising engine RPM.