Sunroof drainage causing electrical damage (2 Viewers)

[Prendo]

Our Sahara LC200 has just had both wiring looms replaced. This cost AUD15,000. It was caused by leakage of water through either the windscreen, or the sunroof. Now that the work is done, we want to be certain that there is no recurrence.
I have checked the windscreen and there is no leak.
I removed the three covers from the LHS kick panel.
I have opened the sunroof and poured water into the drain pan, and down the LHS (in Aus, passenger) side.
The water initially poured out near the junction boxes in the LHS kick panels, but afterward this flow stopped and it came out near the mud flap, as you might expect.
Does anyone have any idea where the drain pipe feeds, or what might cause this odd behaviour - that water started to flow out of the kick panel, then reverted to the “expected” drain points outside the vehicle?

 

[Malleus]

This happened to me two years ago. I wasn't happy.

 

[Sandroad]

Our Sahara LC200 has just had both wiring looms replaced. This cost AUD15,000. It was caused by leakage of water through either the windscreen, or the sunroof. Now that the work is done, we want to be certain that there is no recurrence.
I have checked the windscreen and there is no leak.
I removed the three covers from the LHS kick panel.
I have opened the sunroof and poured water into the drain pan, and down the LHS (in Aus, passenger) side.
The water initially poured out near the junction boxes in the LHS kick panels, but afterward this flow stopped and it came out near the mud flap, as you might expect.
Does anyone have any idea where the drain pipe feeds, or what might cause this odd behaviour - that water started to flow out of the kick panel, then reverted to the “expected” drain points outside the vehicle?

Perhaps there was a minor blockage, enough to divert water inside, until you poured a lot of water quickly that flushed the blockage and got the drain flowing again. Get a drain cleaning tool and clean them out just to be sure all the debris is gone.

 

[linuxgod]

The drain is just a rubber tube that connects to the sunroof channel. My hunch is that you had a blockage, which was causing water to back up and drip, but the blockage freed itself hence the water stopping from coming inside and then dripping where it's supposed to.

Definitely snake out that tube to make sure its clear.

Honestly after spending 15k on a repair I would suggest disconnecting the battery and then pulling the A-pillar interior cover (which has the airbag in it) in order to trace the tube and make sure there's not a slow drop.

Also water is known to come in through not just the windscreen (especially if it's been replaced) but also from the fresh air intake, so check that area thoroughly. A number of people have found small leaks and either replace the cowl or fabricate something to make sure water drips to the side.

 

[Malleus]

I my case the connectors between the cowl harness and engine harness and the ECM were completely corroded. Probably due to the water sitting in the kickpanel well and adding too much vapor in the cabin, confined behind the cosmetic panels, but no one knows for sure.

 

[grinchy]

I mechanically fixed it by putting vinyl over the sunroof. That doesn’t address the cowl leak, or far more rare roof rack foot leaks.

My leak was a blockage, but then the cleaning tool poked a hole in the tube just after the sunroof connection. It’s in an incredibly hard to get to location, so I just blocked the rarely used sunroof. Moon roof is still an option.

 

[bloc]

I mechanically fixed it by putting vinyl over the sunroof. That doesn’t address the cowl leak, or far more rare roof rack foot leaks.

My leak was a blockage, but then the cleaning tool poked a hole in the tube just after the sunroof connection. It’s in an incredibly hard to get to location, so I just blocked the rarely used sunroof. Moon roof is still an option.

View attachment 3489268

What kind of cleaning tool did you use that caused damage?

 

[grinchy]

The dedicated brush and steel line one off Amazon that is linked around. I was either too forceful or my hoses too rotted, or both.

The root cause is the three 100 ft pine trees on my city lot dropping crap on my truck year around. Not even Toyota can plan for that.

 

[Prendo]

I used an electrical cable to clean out the drain. It fed all the way to the bottom panel, where we could hear it moving. I have heard that pine and casuarina trees are the main culprit for blockages.

There have been other issues since the repair. Sunroof buttons are not correctly wired (can’t positively close the sunroof) and the reversing camera has stopped working altogether.

The car is back with Toyota now, so I’ll let you know what they find.

 

[sirchek]

For me, the leak was underneath the cowl. There's a wire that attaches to the bottom of the windscreen. It was clipped on upside down and caused water to travel down the wire when it rained into the air filter compartment. I believe this is what killed my backup camera computer.

This video solved it for me:

However to clean out my sunroof drains I use weedwacker line and boiling water

 

[Prendo]

For me, the leak was underneath the cowl. There's a wire that attaches to the bottom of the windscreen. It was clipped on upside down and caused water to travel down the wire when it rained into the air filter compartment. I believe this is what killed my backup camera computer.

This video solved it for me:

However to clean out my sunroof drains I use weedwacker line and boiling water

I know that issue: we took the vehicle back to the installer and showed them the leak, dripping through the cabin air filter and onto the middle of the floor. That was a separate issue!!

 

[Prendo]

Got the vehicle back from the Toyota dealer, with the leak fixed and the sunroof fixed: it now works correctly!

They had not “performed an operation that is in the service manual”. I’m guessing that it needs to be initialised, not just connected to power. (Big of them to admit fault!)

Reversing camera still not working, but we are now back on the road, and within the legal limits for weight. Whew!!