Massive amount of water in battery tray and spare tire well

Well, my buddy's wife had an issue with his '06 Prius this morning and I went to his wife's job to check everything out.

Was throwing a P3190 code and I decided to take everything on the induction system apart clean the MAF, check all the connections, etc. I had him take the back panels apart to unplug the battery reset the ECU and there was a massive amount of water in the spare tire wheel well. Drained the water, and buttoned everything up and took her for a test drive and we still heard water sloshing around in the trunk. Park the vehicle and take a look and what we didn't notice was that the battery was 3/4 covered in water.

The car was running well again and we drove it about 10 miles back to my place to take a look at everything. We drained all of the water out of the battery compartment (had to be close to a gallon of water) and took apart the entire rear passenger taillight assembly and the top bolt on the light was only just hand tight (culprit?). I cleaned all the surfaces, and put the light back together and performed a leak test and everything looked good, but I was hearing a slight drip. So I really started looking really well. Turns out there was a pretty good leak coming from a metal vent that was about of foot or so right from the middle of the latch and it was definitely coming from under the bumper.

So, we got to drop the bumper.

Turns out there is a metal seam that is just under the tail lights on both sides of the car that is held together with a few spot welds. The piece that comes from the bottom of the car, lays on top of the piece that is under the taillight and is just tacked on.

Interesting enough, this seam is not covered with any seam sealer. I applied some silicone, got lunch and ate it in my drive way, and then tested the seal with some water - GTG. If anyone is looking for a leak in there trunk hatch area, this may be the source. I would suggest getting some actual Auto Seam Sealer Caulk for the job.

What sucks is that you can only seal the outside as the inside of the seam is hidden under more sheet metal

I should have taken pictures, but I was working on the car nearly 5 hours (and I had help) at this point and I was just wanting to get it done.

 

Thanks for the suggestion. We checked all the usual spots with water and it seemed to only be coming from the area that we identified, but I will let him know to keep his eyes peeled.