2011 508 SW Electical gremlins... help!

[RossJ]

I know this isn't about the RCZ so mods feel free to delete this thread if it's nto allowed, but I am an RCZ owner who recently bought my SO a 2011 508 SW. It was all fine on the test drive and for a few days afterwards, but has now started showing some strange behaviour and I'm struggling to find any helpful info online.

It has a RT6 head unit with the same screen and software as my RCZ (with the large popup screen), but often when starting the ignition the screen comes to life and then goes black after a second or two. It's only the backlight, as in the right lighing you can still see the image on the screen and all the buttons still work, just no backlight. The night-mode button (crescent moon) has no effect other than turning the image on and off completely.

Also the air-con sometimes works and sometimes doesn't, the control panel functions normally, the lights come on, but no cold air on some journeys, on others it's icy cold as normal.

These two issues may be linked, as when the screen is not working the air con seems to not work, and yesterday she said she was driving along the dual carriageway and suddenly the screen came to life and at the same time the air-con started blowing cold. Coincidence or not? Additionally, drivers side central air vent is very weak compared to the rest, no matter what the airflow adjuster is set to.

I've tried multiple BSI resets, and when I do that the screen is fine on the first boot, stays on right up until you start the ignition and then the backlight goes out. If you repeatedly take the key out then put it in and turn to ACC it comes on and stays on maybe 1 in 5 times.

I'm running out of ideas, is this something only a Peugeot dealership will be able to diagnose?

Thanks for any insights anyone might have!

 

[Pedro]

Check Battery ?

 

[RossJ]

It hasn't had any issues starting but you could be right. What's the best way to check battery health? Read the voltage across the terminals while running? It does come on eventually after putting the key in and out a few times so could it still be voltage related?

 

[RCZIain]

I had a 508 GT, that liked to act silly until I had a new battery on it.
Peugeot managed to completely kill all the buttons on the dashboard in the process.

 

[RossJ]

Just to update the thread for anyone finding it in future, I solved the issue, but never confirmed the cause.

Long story short, I removed and disassembled the screen to do some testing, and when I plugged it all back in again to probe it in situ, it was suddenly working perfectly.

I suspect it was the connectors for the lcd backlight making a poor contact, and the process of disconnecting and reconnecting them to the pcb sorted the issue.

The air-con issue was the compressor clutch coil was open circuit. Replaced that (not too bad a job if you take the front wheel + arch liner off to get better access) and A/C works perfectly now.