I have experienced electrical problems on two occasions now during multi-day periods of heavy rain.

Vehicle: 2010 G37x - most options except the Technology Package; purchased used this year

Incident 1 (month or two ago):
Driving to work in the morning when the vehicle starts complaining that the key is not present with both the key warning light and the prompt on the dash display. A few moments later the trunk opens all on its own.
Did not notice any other symptoms, but did not use any of the features I will mention in Incident 2. When I closed the trunk after stopping I found that I could not open it by pressing the button on the trunk (proximity of intelligent key). It is possible that the vehicle failed to lock when I left it to enter work. When I left work everything was working normally; and everything has been fine since then.
Wrote the event off as key malfunction due to inadvertently pressing truck release.

Incident 2 (now):
Can open the driver and passenger doors as normal via proximity of the intelligent key; however the trunk will not open this way. Using the button next to the steering wheel works fine (so it has to do with the key and not the trunk mechanism). I checked the valet button in the glovebox, has no effect on state.
When I start the engine the key warning light stays on, but the dashboard display never provides its prompt. The engine runs uninterrupted, no problem, but when I finally stop the engine the vehicle will not start again unless the power is completely cycled: disconnect the negative lead of the battery for 30 seconds. The vehicle starts exactly 1 time per power cycle or overnight rest.
These additional symptoms are not affected by power cycling:
The dome lights are not working whether automatically or via manual activation; the "map light" is lit as normal.
Sunroof does not work. Checked for signs of leaks by gently running my fingers around the space below it, found a bit of grease but no water.
The door lock buttons, including those on the key work for unlock, but not lock. I can use the key fob, double click the door button, or press the unlock buttons on either front doors to unlock all of the vehicle's doors; but I cannot lock any of them without manually throwing the locks.
The windows on all 4 doors do not work; checked the "disable" button on the driver door and it has no effect.

I have tried both of my intelligent keys with the vehicle, both perform identically.
I have checked the fuse for "Interior Lights" (I think it was), and it is intact, replaced it with the spare and had no effect.
I do not know the locations of the fuses for the roof or windows; presumably in one of the two banks in the engine compartment which I am wary to mess with while it is still drizzling.

Because both incidents have occurred during rain, it seems logical to assume there is a water leak resulting in shorts; however:

• Where might this leak be? How could I find it?
• Wouldn't that result in blown fuses?

Thank you for your assistance.

Update 1:
By disconnecting the negative battery lead for 4 hours I was able to clear the key issues; the key light no longer comes on after the vehicle has been started, and it starts reliably.
The other issues (lights, windows, etc.) remain.

Update 2:
I have taken the vehicle to an ASE Master Technician who checked various connections and possible points of ingress for water. He did not discover any discernible wetness and found all connections to be good.
His suggestion was to take the vehicle to dealership to investigate the possibility that the BCM has failed, or requires a reset. It may also be possible that controllers for the windows simply need to be reset.

Update 3:
Took the vehicle to Infiniti dealer. They found water under carpeting on passenger side. Said that if the water came from a leak above it likely would have entered around the windshield. Diagnostic work would be disassembling dashboard to test for water leaks.

Update 4:
Took vehicle to original ASE Master Technician who disassembled dashboard and performed diagnostics to identify leaks. Unable to identify leaks; did find toasted BCM along the way. Given that water is present and no leaks can be found, deductive reasoning indicates that the water came from below. Invoking comprehensive insurance to cover apparent flood damage.

 

You should have done that in the first place

Telcoman

 

Did you fix the problem?

 

OP last posted on Dec 10, 2015.

 

 

^^
You can either pay the dealer the $170 to diagnose the problem or just sell the vehicle.
No one works for free

Telcoman

 

There's a known issue with water leaking from the sunroof drain firewall bulkhead (as I understand it) and it has been known to soak, I think, the BCM. If your BCM is waterlogged, your lights certainly could be "on". I've seen what happens when BCMs are damaged, either by car fire or flooding, the lights get stuck "on".

You probably should trade the car in if you are averse to fixing it yourself. This issue doesn't concern me because I can work on cars, but it can be hugely expensive to pay a dealer to solve the problem. Often, the wet BCM can be dried out and the water leak repaired and everything will be OK. But, a dealer ain't gonna bother doing you no favors in drying out a BCM, they'll just hit you with a huge bill.

 

Or ... the IPDM, which is mounted on the engine side of the firewall, behind the battery. This black box / fuse box has most of the lighting relays in it. And because of its location can be susceptible to getting wet, especially if the body drain lines are plugged, the windshield shroud is not properly seated, or the IPDM cover itself is broken or not in place.

The BCM is the brains but the IPDM does most of the power routing. If either of these components gets wet all kinds of weird s#it can happen.