I have a 2003 LS430 great car 129000miles on it. My fuse box in the trunk got wet and I mean really wet. No I got no tail lights break lights full door won't open trunk won't open no radio fule gage dont work checked fuses cant figure out the problem. I did dry out the fuse box. Took it apart cleaned it with contact cleaner put grease on the connections. What am I missing 😕?? Any help greatly appreciated. Thanks Shawn Hughes.

 

I would assume there is a fuse or circuit breaker under hood that supplies the power for that entire box.

 

I'm going through this very exact thing with my 2002 UL. One day my trunk would keep popping open and close, fuel gauge not working, gas door randomly opening.

When I opened the trunk on the bottom left side it was full of water and the harness was under water right next to the fuse box. An indy took a look at it and told me he got in the trunk with a flashlight and had someone run a hose over the trunk and saw water coming in behind the taillight. I'll take my car in to a body shop and see if they can find where the water is coming in through. Let me know if you have any luck.

Thanks.

 

That is where I think I came in too "around the tail light." I took my fuse box out and apart, and it looked like it was not the first time it was wet. I ordered a new or used fuse box. I would take yours out and clean it up with contact cleaner and let it dry out for a couple days. Then try it. Hope it helps. Shawn Hughes

 

Thanks, I'll pull it out and clean it.

Take out all the fuses and relays and wipe them down with contact cleaner?

I'm looking into taillight gaskets if that could be casuing it: https://www.lexusoeparts.com/oem-par...0aAuWxEALw_wcB

 

Thats what my fuse box looked like!

 

That's not just a fuse box. It has several Integrated Circuits and if any one of those has been damaged by a short circuit caused by the water nothing will work.
You may be able to get that working again, but I think it'll be cheaper and simpler to just replace it with a working used item.

 

The upper right part circuits handle more than 150 watts of power to supply the +B 12V to tail light bulbs. The most of components there are supplying and checking the current to bulbs as are explained the detail here. So it is natural that your tail lights are stopped working due to the corrosion. The dry out and the cleaning will not be enough to let the board to work again. As BigBoomer suggests, it'll be the best to replace the board with a working used item. You probably need to deal with connectors too. The polishing the surface of contacts and applying Toyota connector grease 08887-82106 may help the conductivity stable but badly rusted connectors will not be recovered.

 

I had the same thing happen to me in my 04. I let it dry and now my tail lights don’t work at all. At first it was staying on and draining my battery. Now I think they res a short somewhere.

 

Put a few containers of Damp Rid to get any remaining moisture out from the trunk area to start with.

 

I had the exact issue. The tail light gasket was missing. Remove the tail light and check if the gasket is ok. If not - you can DIY it.