just1time

The 2013 G63 has been driving very fine since I got it.
Took it on a trip to the cottage (which it has done lots of time before). After a 3hr drive back to the city, I stop at FedEx to pick a package. Come back and start the truck and all lights on dash come on. Whole instrument cluster lit up like it’s Christmas. Gauges not working (tachometer needle comes to life sporadically like its in shock and dies, Temperature gauge doing the same. Gas gauge working. Speedometer needle not working).

Car drives absolutely fine despite all this. Even ECO start/stop works fine. I drove it home without issue and parked it. Will check up on it when weather cools off in the evening. I did notice the fan was going louder than normal after i shut the truck off.

Anyone experience anything like this?

Not sure if this is a contributing factor but It is particularly hot today in the city. I should also mention that over the last month and a half I randomly got the AAS defective warning a couple of times when I started the truck. But it always went away when I turned the truck off and back on. (Research indicated this was a common sign of a dying auxilliary battery)

just1time

Just went back downstairs after a couple of hours. and everything seems to be back to normal.
I will still go ahead and run a check at my mechanic to see if it reveals the cause of what happened.
if anyone has any idea, please chime in.

chassis

When were the main and aux batteries last changed? If less than 4 years, replace the both, on principle. Then see if the error lights and messages return.

Hodog16

Usually things like this are due to the batteries. Easy place to start for sure.

bullrider313

Hi
can you please post what the solution was. I have the exact same issue and replacing the aux battery didn’t resolve it. I’ve torn my whole truck apart looking for a water leak, corrosion on the connectors and anything loose. Can anyone please advise. Thank you

PeriodCorrect

Did you replace the main battery?

bullrider313

no not yet. It tested fine and appears to be a brand new Mercedes Benz battery. I guess it can’t look old because it’s inside under the rear cup holders. It’s worth a try.
it’s weird, I had the issue non stop for a week and then it goes back to normal for a hour, day, or week. It’s very random and frustrating.
I noticed the original poster posted the issue and then posted the issue again a year later in another thread so it must come and go. I will definitely post the solution when I find it. Thanks for the help.