A couple weeks ago I changed a brake light bulb, started the vehicle and the VERY INSTANT I touch the brakes, I get a HDC light, along with Transmission error. Not to mention, neither of my brake lights are working now... I did notice the wire assembly for the bulbs is corroded, and chipped in places where the bulbs are inserted. After some research I read of using aftermarket bulbs causing similar issues. And I indeed did use aftermarket bulbs 😫😭. I checked the brake light fuse, or at least I'm pretty sure it was the correct fuse... And it isn't blown.
On top of that, I open the passenger door to be greeted by an enormous puddle of standing water.....I was almost positive my issue was a clogged sunroof drain. At the time, the ride height was damn near sitting on the tires all the way around. The moment I raised the ride height, water began draining near front passenger door. At this point I checked the sunroof drain by pouring water on the sunroof to verify water was flowing, and it was. Is it possible when the ride height gets SO low, it is kinking the drain? Possible my leak is coming from elsewhere? If anyone can share their knowledge it would be greatly appreciated! Also I forgot, pretty sure there is a leak in the front right air bag, it slowly lowers itself over time.
Thank you for any and all help!

 

I am also having some issues with my sunroof drain on the right side of my 06 RR HSE. I will be changing out both sides here pretty soon. I cant say I've experienced large amounts of water as you described. At least not from just a faulty sunroof drain. Then again rain is not as abundant where I am located as it may be where you are. I've heard about leaks from the vent box area under the windshield cowel in the engine bay. I think there are 2 M8 screws that hold this box in place. I personally have never experienced this but I have heard about a loose vent box with a bit of a space behind it that resulted in wet floors and water ingress into the cabin. Its worth a shot to take a look at it. I highly doubt your suspension height has anything at all to do with water ingress. I'd also get some electrical part cleaner and clean the wires you came across while changing bulbs or any others you suspect came into contact with moisture. It might also be worthwhile testing your battery. A faulty battery causes all kinds of electrical witchcraft. If you have a substantial amount of water, I hope not, but you may have gotten your main harness wet which will also result in a bunch of electrical mishaps. If this is the case you will have to remove seats and pull up the carpet to dry everything down. I doubt this is the case but it has happened to people in the past. I would first check both right and left side sunroof drains all the way from sunroof to exit point. Then I would check the engine bay vent box to see if there is any signs of water ingress behind it when you pull it out. Just my 2 cents.