So recently we had a huge downfall in SoCal. Long story short I drove through what I though would be a normal puddle and it wasn’t. Now the issues I’m experiencing is intermittent starting issues (Sometimes the car will start no problem. Sometimes it takes several attempt to get the starter to kick.). Also have an intermittent issues with the stereo (Mark Levinson), Climate Control and rear view camera not working. I changed all fuses and even the starter relay. Inspected all the fuse boxes and they look dry. After reading a few threads I see people have recommended changing the luggage compartment fuse box. Also saw someone recommend changing the AC amplifier (I get a check AC connection message when the climate control refuses to work). And the head unit for the stereo will power on but no sound. Other than that, everything else works. Where should I start? Is there an ignition relay under the fuse box in the engine bay? From diagrams I looked at, it seems there is two relays located under one of the fuse boxes. Also did the secret diagnostic manu on the nav screen during one of the times the climate control/stereo and reverse camera were not functions and this is what came up

 

If you have waited a few days for everything to dry out, then try disconnecting the battery, waiting 15 mins, then reconnecting it.
That resets all the various computers and everything starts from scratch.

We have had a lot of rain here recently too and the number of people who try to drive through clearly marked fords (no, river-fords, not the cars!) is amazing.
Someone I know tried to drive his snorkel equipped Land Rover Discovery through a 4' deep ford, but his car floated and the current pushed him downstream where the river is 10' deep.
He got out through the sunroof and got to safety but the Disco needed a full engine rebuild after it was towed out of the river.

What is worse are the idiots who swerve into oncoming traffic to avoid a puddle.
Apparently getting hit head on is preferable to driving through a puddle or just waiting until it is clear to drive around it.

 

I’ll try the battery disconnect tomorrow. That and a few relays are the only things I haven’t tried yet. I’m wondering if anyone has a description of what each relay does. I know I’m the underside of a fuse box or two there is a relay for Ign and Acc. Just wondering exactly what they are relevant to.

 

So I did the system hard reset. Everything worked for a day. Then after I left work it went out again. Today after I left my day job it all came back on while driving. Pretty sure I might have to replace the rear luggage compartment fuse box.