Hello, I am new to the CL forum's. I purchased a 2001 Lexus LS430 UL back in February 2023 the listing stated that the car had a battery drain issue and was believed to be the aftermarket radio that was installed. Luckily the owner had kept the original unit. I went to meetup with the owner to test drive it. Seller sold it to me for 2,000 USD. Checked air suspension, rear blinds, automatic door worked. While I was checking out the car seller told me that the car's fuel gauge would work and sometimes wouldn't in my head I am thinking "maybe it's time to replace the fuel pump". Given the price I bought it for I expected unseen issues and as usual they checked out. Next day I was sitting outside admiring my newly acquired LS430 as one would. I noticed that the car's tail lights would turn off then on off then on. I am thinking BINGO I FOUND THE ISSUE, so I thought I did. One morning I was headed to school to bring it to the shop and put the car on the lift I noticed that the right side tail light had blown up. I am thinking must've been what I was seeing last night. One trip later to Autozone changed it everything worked. It was around 1:40 and the school closed at 3:00 so I wanted my climate control back so I changed the unit and was hoping maybe this fixed the issue but as usual hell no, but I had A/C again. As I was about to leave one of my classmates pointed out that my car smelled like fuel. As I remember the car came with parts that they had changed I found a receipt for a fuel cap, light socket and for a solenoid at the time I wasn't sure what it was for until I did some research it was for vapor canister purge solenoid. On the way home I smelled fuel and as I am putting two and two together I was under the impression that maybe I was leaving a trail and nothing. Next day I take it back to the lift and I found the issue for the battery it was a broken ground cable as seen on the picture below. I found more issues like oil leaking, oil buildup, lower control arm needed to be replaced oil change, air filter. The car would start up every time no issues. HOWEVER, I remember I took my car to the car wash and 2 days later it started raining consecutively and that's where **** really hits the fan. The car would struggle to start and I noticed it to my big ****ing surprise car is struggling to start again and then nothing. I still to this day don't understand how it went through my head that these cars are known for having water leaking issues in the trunk area. As my curiosity got the better of me I check the trunk and yep there was water just sitting there for god knows how long. I drain the water out upon closer inspection water must've been here multiple times I see. But what doesn't make any sense to me at all is before I checked that area my tail lights would work fine everything except my trunk and fuel door. As I recall there would be times where the trunk would want to open by itself and then nothing. Anyways, I open the fuse box and I see corrosion, rust and for what it looks like burn marks. As of right now I think I found where the water is getting through and trying to find a trunk fuse box to hopefully repair my fuel door, trunk, parasitic issues. Hopefully this is the answer to why it keeps draining battery. If anyone has suggestions or something similar would be much appreciated.