Misstootie1

Hi all, I'm new here and a new Lexus owner. Just bout the car last month. After it rains, I have water in my trunk, and hoping it's just a gasket around my tail lights. Anyway, after water gets in, I have crazy electrical issues, that differ slightly each time. Mainly my instrument panel. Speedometer, fuel level, and temperature gauges don't work. Also abs/ brake warning light on, hazards on, windshield wipers work only on high, outside temp does not work, now climate control doesn't work. After drying out, everything is back to normal. Today I dried it out, but still issues persist. Ordered tail light gaskets, so hopefully that will solve the leak, but I'm really worried about this.
there is a box in the trunk on the driver's side. Is it a computer? Could that be going out?
Any help or insight is greatly appreciated!
Love this car and hope it's not a money pit! Drives great!
Thanks so much in advance!!!

LatinLS430

iTrader: (1)

This video will be very helpful to you

Misstootie1

Well, darn. Since I already bought the car it's too late to walk away, and this is my only vehicle right now. Any suggestions as what else to do? Replace the computer? Anyone know the name and part number for this computer?
thanks!
PS: still hoping if everything dries out it will go back to normal. Had to disconnect the battery because the hazards won't turn off.

LatinLS430

iTrader: (1)

How many miles are on your car?
Can you see where the water is coming from?
I'm sure you can buy a computer on eBay. Not sure what part number it would be or which one, sorry.

TominPT

Suggestion - before you replace the computer or anything else get the root cause of the water intrusion and fix that first. Otherwise history will repeat itself. Not sure if Car Care Nut covers the actual leak (sunroof drain perhaps???) in his video.

Misstootie1

It's got 193k miles. I bought the tail light gaskets since that seems to be where the leak is coming in from. So is the computer in the back called an ecu? Not sure how to word it to search for the part to replace.

LatinLS430

iTrader: (1)

The ECU for these cars are is in the engine bay.
There's some other computer stuff in the trunk. Are both of your sides leaking?

Misstootie1

Yes, both sides are leaking. The wetness appears to be coming from the tail light area, as the back walls underneath them are wet. And small puddles of water behind the box on the driver's side, and the amp and navigation box on the passenger side. Will probably take it out to see if I can get it thoroughly dry. Had a fan on it for several hours today, to no avail.

alextv

In driver left wheel well the smaller box is the telephone transceiver and speaker relay. The bigger box is a fuse box and that is where your problem is. Disconnect battery and take fuse box apart and try to clean any apparent water damage like corrosion. This is a known problem when water leaks into the wheel well and some have had to replace that whole fuse box assembly. Water has got to be kept away from the trunk.

Misstootie1

Thank you all for your input! That is exactly what we will do; we had to do the same thing with my husband's truck fuse box. Fords of certain years had a known leak in the windshield and water would run into the fuse box and the GEM. Hubby took ALL of it totally apart and cleaned them.
To be on the safe side, I just bought a used one on eBay for $130.00, as the part is hard to find. Only found one Lexus OEM parts dealer that had one (new), and it is $850! if my original box cleans up and works, I'll just have a spare handy. By the way, for future reference for anyone else with this problem, the part is Lexus 82670-50073 Block Assy, Luggage Room Junction.
Thanks again!

TominPT

Good luck Misstootie1. I just wanted to mention that you might be right that the tail light gaskets are the culprit. But, if your car has a history of being parked outside and/or you live in an area where there are lots of pine needles that accumulate on the roof of the car, the sunroof drains can clog eventually and water will appear in the areas where you are seeing it. If I was in your situation I would want to be 100 percent certain that your drains are clear before you replace your electronics. In other words you could be looking at two different sources of water. One way to check would be to open the sunroof, pour a little water around where the drains are, and verity the water is trickling out onto the ground shortly after you start adding water. There may be two drains, one on each side of the sunroof, I have not checked my car to be certain. If water is not trickling onto the ground, its going somewhere else - into the car presumably. A long piece of weedwacker string from one end of the drain to the other can "floss" the drain and clear it (if need be),.

alextv

I would install the used part and keep damaged part for spare. You might think you cleaned it and in the process shorted something else out and permanently damage some other part. Hidden corrosion is very hard to clean and being moistened could create another short. If you didn't have the used part I would clean and try. I have over 30 years experience of electronics repair with water damage and majority of times could repair. Take a picture of connectors before disconnect.

Misstootie1

Thank you so much! I will definitely do this!

Misstootie1

Oh, fore sure! When my husband took his fuse box and GEM and took them apart and cleaned them, he was super careful to make sure everything was bone dry, (several days!) then sprayed everything with silicone spray before putting everything back together. Worked great.

Bocatrip

Trunk leaks in the LS430 are common. Even after you locate the leak, it's always a good idea to get rid of the leaves and or debris that collects in the channels along the top and sides of the turnk so that the water can drain properly.