Rear Seat Belt Corrosion!

it is corrosion. your zinc parts are in contact with carbon steel parts and possible nickel cad bolts. its just like battery terminals. 2 dissimilar metals in contact of each other with naturally corrode. Especially when there is electrical current flowing through the body of a truck. And no i dont mean that in a way that you will feel electricity or get shocked, but your battery and electrical system grounds to the body. Add moisture from underneath where the bolts attach and it does this. just like above, its not different than cad plated battery terminals getting attached to lead posts.

 

was looking for mold from a leaky 3rd brake light, but not seeing evidence of that.. however i would clean up ASAP, and keep an eye on it, especially during/after a rain storm.. make sure carpets stay dry, and you dont have evidence of the rear window/light leaking. maybe throw a bucket of DAMP RID in the back seat, if you live in a humid loaction...

 

Moisture getting around metal parts .then they start to corrode over time .

 

https://youtu.be/h46w7LfjQxw?t=63

 

I live in Salt Lake City. Ok I'm glad to have this shit identified. I'll try cleaning it up. Also, I never thought a third brake light could leak. Gonna check that too.

 

Definitely check 3rd, very good chance that's it

 

This ^^^^

 

Yeah, it's not unique to Toyota. Although Toyota's is far more of a pain in the ass to fix than my GMC. No issues for me so far, but plenty have had the issue. It'll look as if your rear window is leaking. Another indicator is if you find any moisture in the housing itself. But just because it appears dry doesn't mean you don't have a leak. A bead of silicone will work too if you don't want to go through the dealership fix.

 

You’ll know a 3rd brake light leak if you see mold under the carpet of the rear seats, Or carpet is damp. Run your hands under that carpet on both sides. Water drips down the back window, behind the panels and is hard to spot if you don’t know what your looking for.

 

So as I write this my truck is in the shop, will be for another week or so as I discovered that my 3rd brake light was leaking and getting carpet wet, as well as headliner and seats. Anyway I was able to convince toyota to cover it even though it is out of warranty. So they are also replacing all of the sound mat and all things that got wet. Mine was so bad I actually had mold. So I would suggest using your camera on your phone to take pictures of the headliner and seats, due to light filtering of your camera it will show what you cannot see.

 

Looks like terminals on an old lead cell battery.

 

It depends when the last rain was and given that OP is in Utah, I don't know how recently that would be.

 

“Mold” and Toyota usually equals “goodwill”

 

Take this in asap unless my eyes are deceveing me the webbing broke and that buckle isn't even attached and will pull right off.

 

Update: I know it's been a while. Took it to the dealership, they wanted $170 just to "look at it and figure out what's wrong." Over the phone I was told I wouldn't be charged for a diagnostic. Turns out that was a lie.
My plan now, rather than pay damn-near $200 to have them just "check it out," I will try to remove, clean, and replace the bolts myself. Also, turns out the seat belt receptors themselves are also covered in rust. I'll be trying to fix that myself as well. Will start another thread.

 

Also, no sign of a third brake light leak. My rear seat carpets and seats themselves are fine. Totally dry. Someone in this thread earlier said its moisture from underneath. Also, the zinc connector corrosion issue makes a lot of sense. Not sure why they would use zinc. Will be using a lot of silicon to remedy this.

This has left such a bad impression of Toyota with me.

 

Yeah but did you taste it?

 

Let's just say, this has left a really bad taste in my mouth.

 

Corrosion sucks. Sorry you're dealing with this. That said, no vehicle is completely immune to rust or the ravages of electrolysis. Being proactive with rust prevention measures (using Fluid Film or the like) takes up a chunk of my yearly winter vehicle maintenance. I highly recommend looking in to it. However, even with those added measures and care, it's not a cure-all . In the words of the great Neil Young, rust never sleeps.