Water from heavy rain causing shorts/faults

[VasKav]

2000 Landcruiser, 166K miles, 2nd owner. I've had it about 10 years, prior to me it baked in the SW desert. Every belt, hose, rubber bushing was cracked and over time replaced. Wiring on the whole has been stable, except for cracking/shorts in the door hinge harness but those have been gone through.

10" of rain in CA over last week, cruiser not garaged. I drove yesterday and after about 50 minutes, started seeing AT Fluid Temp light. Stopped immediately, fluid levels fine, condition of fluid seemed fine, temp to the touch was not even that hot. Hmm. Rest it for a bit, drive some more, then check engine light goes on. Then it starts to misfire/stall at idle. Then VSC lights. I just stopped driving, left it over night in a safe spot, had my daughter pick me up and bring me home. No rain, bit of sun this morning. Went back this morning, pulled the codes - 9 fault codes, 2 crankshaft position sensor, 2 abs, misfire, etc. I cleared the abs faults, restarted the truck, all lights off including check engine. I drive cautiously, after an hour no faults, no check engine, running and driving fine.

So, I figure I have water getting in somewhere and likely causing shorts/faults. It does have a sunroof and I noticed the headliner is wet on one corner. I cleaned those drains not too too long ago but I'll do it again. Maybe I didn't really get them clean. I'm very concerned that is potentially not the only location leaking.

Any tips for where/how to check for leaks? Any thought based on the number of faults where that leak may be? What elecotronics were being impacted? I'm decent with mechanics but electrics are a black box for me

Thanks!

-Simon

 

[dbfw]

I think the usual culprit would be the fuse panel in the driver's footwell. Clogged sunroof drains could cause water to accumulate there. Leaking windshield trim is another potential source of water down the A-pillars. If your headliner is visibly wet, I'd probably lean toward sunroof. If you pour some water in the drip tray, does it quickly drain out? It should, so if it doesn't more prodding of the drain tubes might be necessary. I think some folks have checked for leaks by turning the HVAC on high and set to fresh air in an attempt to somewhat pressurize the interior. Then, mix up some soapy water in a spray bottle and go around different areas to look for bubbles. Keep in mind the rubber seal around the sunroof glass where it meets the body isn't meant to be 100% watertight, that's what the drip tray is for. If I were doing that test, I'd probably focus on the windshield and if you're good there, then just make sure your sunroof drains are totally clear.

 

[silvarshooter]

I just dealt with snow melt causing electrical gremlins in the passenger kick panel, I only got a PO750 code and doors repeatedly unlocking for a few minutes. Is your carpet wet? Pull your kick panels and see if your terminals are getting wet. Sound like they are so disconnect the battery and start unplugging , takes patience as some are a pain but once unplugged if you have a compressor blow them out and then give a quick blast of terminal cleaner. This solved my issue on the gremlins but I’m still dealing with the drains as they’re currently frozen.

 

[VasKav]

very helpful guys - thank you. I’ll try to get behind those panels on both sides. I did the sunroof drains again but honestly, they seemed to be flowing ok before cleaning. I’ll keep searching for leaks.

 

[Trunk Monkey]

If you've had your windshield replaced, that's a common one. Spray something soapy along the outside border, blow compressed air from the inside all around the edge, see if you get bubbles.

 

[Smiles]

One of the lesser known and less likely water entry points that could affect the headlining, are the roof rail bolt holes, the holes are not blind so they go right through the roof, the bolts are seald from the factory but as we all know sealant can fail over the years, I don't think this is your problem as you would have tell-tail sings in the headlining in other places.

As Trunk Monkey said, has your windscreen been replaced to your knowledge? the problem is not nenecessarily with the sealant or it's application that is applied to the screen around it's perimeter, as most windscreen replacement centres are very good at their job, but, what very often gets overlooked, is the removal and fitment of the 'outside mouldings' on left and right side of the outside of the screen, the mouldings have nothing to do with holding the screen in place, they are more to to with form not fuction, perhaps they do channel water.

The mouldings are held in place by 8 special 'pop rivets' part number 9026904053, when the mouldings are removed by drilling out of the pop rivets it is very, very important that the drill bit is not biger than 4mm, otherwise the new 'special' pop rivets will not grip when reinstalled, and will let water in that will trickle onto the fuse boxes behind the passenger and drivers footwells kick panels.

The rivets are 'special' because they have a plastic cover over them that seals the hole as they are crimped, I have even seen the mouldings fitted with 'self tapping screws' (a big no,no)

Here is a picture of said rivets. And is very important that these rivets are used and not ordinary pop rivets. Sorry if this has been a bit long-winded. Just trying to be helpful

And here is a picture of the placement of the outside mouldings and the pop rivets.

Outside No. 2 mouldings are just to cover the rivet heads

 

[Jfcol]

One of the lesse known and less likely water entry points that could affect the headlining, are the roof rail bolt holes, the holes are not blind so they go right through the roof, the bolts are seald from the factory but as we all know sealant can fail over the years, I don't think this is your problem as you would have tell-tail sings in the headlining in other places.

As Trunk Monkey said, has your windscreen been replaced to your knowledge? the problem is not nenecessarily with the sealant or it's application that is applied to the screen around it's perimeter, as most windscreen replacement centres are very good at their job, but, what very often gets overlooked, is the removal and fitment of the 'outside mouldings' on left and right side of the outside of the screen, the mouldings have nothing to do with holding the screen in place, they are more to to with form not fuction, perhaps they do channel water.

The mouldings are held in place by 8 special 'pop rivets' part number 9026904053, when the mouldings are removed by drilling out of the pop rivets it is very, very important that the drill bit is not biger than 4mm, otherwise the new 'special' pop rivets will not grip when reinstalled, and will let water in that will trickle onto the fuse boxes behind the passenger and drivers footwells kick panels.

The rivets are 'special' because they have a plastic cover over them that seals the hole as they are crimped, I have even seen the mouldings fitted with 'self tapping screws' (a big no,no)

Here is a picture of said rivets. And is very important that these rivets are used and not ordinary pop rivets. Sorry if this has been a bit long-winded. Just trying to be helpful

View attachment 3213422

And here is a picture of the placement of the outside mouldings and the pop rivets.

View attachment 3213424
Outside No. 2 mouldings are just to cover the rivet heads

I have electrical gremlins after heavy rains as well. For me, the drive indicator dash light and water temp gauge will stop working. Both will come back on again at some point - at least so far. Unfortunately, my pillar rivet holes were drilled out at some point. Since I can’t use the correct rivets with the covers, should I seal around the screws that are in there with some silicone? Seems like that might help stop potential leaks.

 

[Smiles]

I have electrical gremlins after heavy rains as well. For me, the drive indicator dash light and water temp gauge will stop working. Both will come back on again at some point - at least so far. Unfortunately, my pillar rivet holes were drilled out at some point. Since I can’t use the correct rivets with the covers, should I seal around the screws that are in there with some silicone? Seems like that might help stop potential leaks.

Hi Jfcol,

I don't think sealing around the screw heads will solve your problem, as the water gets in in-between the outside moulding and the A pillar, the A pillar is hollow and open at the bottom, so when the rivet holes are damaged water gets in and finds it’s way down to whatever is below and in it’s path, and usually the first thing of consequence is electrical, after that it's the carpet in the footwells.

As I said before, self tapping screws are the worst, as they not only make the holes even bigger but also raise the edge of the metal as they cut their own thread, also the outside mouldings holes will be damaged, so new mouldings will be needed.

I had the same problem inherited from the pervious owner, and this is my work around and it has worked for the last 9 years with no water ingress.

New parts required but not limited to….

Disclaimer, these are the parts I used on my 2004 LC 100, you will need to check if they fit your model year.

Minimum 8 rivets (I would get 16, 8 spares) Toyota Part number 90269-04053

Right side moulding Toyota Part number 7553360031

Left side moulding Toyota part number 7553460021

Moulding outside No.2 left and right are the same part number 7554360020, they are not strictly necessary as they only cover the rivet heads and do nothing for water tightness. See picture above in my previous post.

Windscreen adhesive kit from eBay, Do NOT use silicone.

I would get 4 new good quality 4mm drill bits, 3 of them are for just-in-case.

Main tools required, but not exclusive…

Small battery Drill, as you will be working close to glass, you don’t want to scratch the glass while the chuck is turning, I used a piece of cardboard between the glass and the spinning chuck, to try to protect the glass as much as possible.

Pop rivet gun, small hand held, there is a ‘special tool’ ‘pop rivet gun’ with a narrow head to enable access to the channel in the moulding when installing the new ‘special pop rivets', I just grinned each side of the head of my pop rivet gun to make it fit, as the correct installation of the new pop rivets is crucial.

A tool to remove the fixings that are holding your existing moulding in, ie, screws or wrong size rivets.

Procedure…

Remove old mouldings, you’ll see that the the moulding are fixed with double sided tape from the top of the screen glass into the gutter, make sure you remove all the old double sided tape residue from the paintwork in the gutter, otherwise the new moulding that come with the double sided tape already attached won’t adhere.

Now is the time to check the flat part of the a pillars for rust rust or wot-not, so in other words the part of the A pillar with the four holes in where the moulding was fixed to, make sure this surface is clean and flat, and that any exposed metal is treated, ie, touch-up paint, if the existing holes have raised edges on them, tap them gently down and in awards to the A pillar cavity, these holes will not be used again.

Use a little of the windscreen/windshield adhesive you bought from eBay to fill the holes, do not use silicone, smooth the adhesive flat to the A pillar while still pliable, so now your A pillar is flat and clean with no holes.
Take your two new moulding and drill four new 4mm holes approx 10mm away from the existing holes in the new mouldings, it’s your call if you drill them above or below the existing holes, you just don’t want them to interfere with the old holes that you just filled/repaired in the A pillar.

Once the new holes are drilled in the new mouldings check for burrs, offer the mouldings up to the A pillars, secure them in place with tape as if they were in their fixed and in there final position, make sure the moulding are fixed very well with the tape so that the moulding won’t move, using the new moulding with the new holes as a ‘template’ (you could temporally blank off the old holes so’s not to mistake them) carefully and slowly take you time to drill four new 4mm holes in to the A pillar using the the new holes in the moulding as guides, make sure your drill is as straight and square as possible, obviously this procedure would be a lot easier if the screen was not fitted.

BTW, if you ever have a new screen fitted, remove the moulding yourself, don’t let the screen fitter do it, because that’s how this all started, in my case the fitter bought new moulding as the existing moulding are not easy to remove without damaging them, I told him not to fit the new mouldings and that I would fit them myself, I had to sign to say he had not fitted the moulding, but at least by fitting myself I had peace of mind that they would not leak.

Finally (yes I know it’s a saga) remove the temporally taped secured mouldings, touch up the 8 new holes to prevent rust, doesn’t matter what paint you use as long as it will prevent rust, as this part of the A pillar is not seen once the moulding is fitted. Wait for paint to dry.

Offer the new moulding up to the A pillar again, this time use the four each side new special pop rivets (do not pop the rivets yet) to temporally check the position and correct fit of the moulding, remember I mentioned that the top most part of the moulding have double sided tape fitted to them, now remove the top three rivets leaving the bottom one in place (this next part is what I found the trickiest) so the bottom rivet is still in place as a guide, then remove the backing covering the double sided tape, (you only get one shot at this part) then carefully and slowly lower the moulding down ( keeping the bottom pop rivet in place, as a hinge (suppose you could say), now press the part with the double sided tape firmly down into the gutter, if you don’t make sure the area is very clean the tape won’t adhere.


Now that the mouldings are in place, and the new holes in the mouldings and the new holes in the A pillars are lined up, you will now see why the pop rivet gun needs to be modified, it’s a tight squeeze, now fit the new special pop rivets in the pop rivet gun, keeping the rivet and gun nice and square to the pillar, you can now place the rivets in the holes and pop them.

This is what I did and it worked, you may find variations on the theme, but the whole point is not to do a bodge-job.

Feel free to ask question or criticise, as in no way do I consider myself an ‘expert’ in any field, every days a school day, free speech is still aloud in my house, as long as you’re not to offensive. Also, please excuse spelling and punctuation mistakes, but I think you'll get the drift.

Below is an extract from the FSM with regard to the fitment of the rivets.

 

[2001LC]

2000 Landcruiser, 166K miles, 2nd owner. I've had it about 10 years, prior to me it baked in the SW desert. Every belt, hose, rubber bushing was cracked and over time replaced. Wiring on the whole has been stable, except for cracking/shorts in the door hinge harness but those have been gone through.

10" of rain in CA over last week, cruiser not garaged. I drove yesterday and after about 50 minutes, started seeing AT Fluid Temp light. Stopped immediately, fluid levels fine, condition of fluid seemed fine, temp to the touch was not even that hot. Hmm. Rest it for a bit, drive some more, then check engine light goes on. Then it starts to misfire/stall at idle. Then VSC lights. I just stopped driving, left it over night in a safe spot, had my daughter pick me up and bring me home. No rain, bit of sun this morning. Went back this morning, pulled the codes - 9 fault codes, 2 crankshaft position sensor, 2 abs, misfire, etc. I cleared the abs faults, restarted the truck, all lights off including check engine. I drive cautiously, after an hour no faults, no check engine, running and driving fine.

So, I figure I have water getting in somewhere and likely causing shorts/faults. It does have a sunroof and I noticed the headliner is wet on one corner. I cleaned those drains not too too long ago but I'll do it again. Maybe I didn't really get them clean. I'm very concerned that is potentially not the only location leaking.

Any tips for where/how to check for leaks? Any thought based on the number of faults where that leak may be? What elecotronics were being impacted? I'm decent with mechanics but electrics are a black box for me

Thanks!

-Simon

Whereas I deal with water entry issues, all to often. Which 9 out of 10 are from imporper windshield install.

In your case "2 crankshaft position sensor, ** misfire,". I'd look at crank sensor wire routing, first thing. If routed wrong it may rub on drive belt, cutting wires.

 

[Jfcol]

Hi Jfcol,

I don't think sealing around the screw heads will solve your problem, as the water gets in in-between the outside moulding and the A pillar, the A pillar is hollow and open at the bottom, so when the rivet holes are damaged water gets in and finds it’s way down to whatever is below and in it’s path, and usually the first thing of consequence is electrical, after that it's the carpet in the footwells.

As I said before, self tapping screws are the worst, as they not only make the holes even bigger but also raise the edge of the metal as they cut their own thread, also the outside mouldings holes will be damaged, so new mouldings will be needed.

I had the same problem inherited from the pervious owner, and this is my work around and it has worked for the last 9 years with no water ingress.

New parts required but not limited to….

Disclaimer, these are the parts I used on my 2004 LC 100, you will need to check if they fit your model year.

Minimum 8 rivets (I would get 16, 8 spares) Toyota Part number 90269-04053

Right side moulding Toyota Part number 7553360031

Left side moulding Toyota part number 7553460021

Moulding outside No.2 left and right are the same part number 7554360020, they are not strictly necessary as they only cover the rivet heads and do nothing for water tightness. See picture above in my previous post.

Windscreen adhesive kit from eBay, Do NOT use silicone.

I would get 4 new good quality 4mm drill bits, 3 of them are for just-in-case.

Main tools required, but not exclusive…

Small battery Drill, as you will be working close to glass, you don’t want to scratch the glass while the chuck is turning, I used a piece of cardboard between the glass and the spinning chuck, to try to protect the glass as much as possible.

Pop rivet gun, small hand held, there is a ‘special tool’ ‘pop rivet gun’ with a narrow head to enable access to the channel in the moulding when installing the new ‘special pop rivets', I just grinned each side of the head of my pop rivet gun to make it fit, as the correct installation of the new pop rivets is crucial.

A tool to remove the fixings that are holding your existing moulding in, ie, screws or wrong size rivets.

Procedure…

Remove old mouldings, you’ll see that the the moulding are fixed with double sided tape from the top of the screen glass into the gutter, make sure you remove all the old double sided tape residue from the paintwork in the gutter, otherwise the new moulding that come with the double sided tape already attached won’t adhere.

Now is the time to check the flat part of the a pillars for rust rust or wot-not, so in other words the part of the A pillar with the four holes in where the moulding was fixed to, make sure this surface is clean and flat, and that any exposed metal is treated, ie, touch-up paint, if the existing holes have raised edges on them, tap them gently down and in awards to the A pillar cavity, these holes will not be used again.

Use a little of the windscreen/windshield adhesive you bought from eBay to fill the holes, do not use silicone, smooth the adhesive flat to the A pillar while still pliable, so now your A pillar is flat and clean with no holes.
Take your two new moulding and drill four new 4mm holes approx 10mm away from the existing holes in the new mouldings, it’s your call if you drill them above or below the existing holes, you just don’t want them to interfere with the old holes that you just filled/repaired in the A pillar.

Once the new holes are drilled in the new mouldings check for burrs, offer the mouldings up to the A pillars, secure them in place with tape as if they were in their fixed and in there final position, make sure the moulding are fixed very well with the tape so that the moulding won’t move, using the new moulding with the new holes as a ‘template’ (you could temporally blank off the old holes so’s not to mistake them) carefully and slowly take you time to drill four new 4mm holes in to the A pillar using the the new holes in the moulding as guides, make sure your drill is as straight and square as possible, obviously this procedure would be a lot easier if the screen was not fitted.

BTW, if you ever have a new screen fitted, remove the moulding yourself, don’t let the screen fitter do it, because that’s how this all started, in my case the fitter bought new moulding as the existing moulding are not easy to remove without damaging them, I told him not to fit the new mouldings and that I would fit them myself, I had to sign to say he had not fitted the moulding, but at least by fitting myself I had peace of mind that they would not leak.

Finally (yes I know it’s a saga) remove the temporally taped secured mouldings, touch up the 8 new holes to prevent rust, doesn’t matter what paint you use as long as it will prevent rust, as this part of the A pillar is not seen once the moulding is fitted. Wait for paint to dry.

Offer the new moulding up to the A pillar again, this time use the four each side new special pop rivets (do not pop the rivets yet) to temporally check the position and correct fit of the moulding, remember I mentioned that the top most part of the moulding have double sided tape fitted to them, now remove the top three rivets leaving the bottom one in place (this next part is what I found the trickiest) so the bottom rivet is still in place as a guide, then remove the backing covering the double sided tape, (you only get one shot at this part) then carefully and slowly lower the moulding down ( keeping the bottom pop rivet in place, as a hinge (suppose you could say), now press the part with the double sided tape firmly down into the gutter, if you don’t make sure the area is very clean the tape won’t adhere.


Now that the mouldings are in place, and the new holes in the mouldings and the new holes in the A pillars are lined up, you will now see why the pop rivet gun needs to be modified, it’s a tight squeeze, now fit the new special pop rivets in the pop rivet gun, keeping the rivet and gun nice and square to the pillar, you can now place the rivets in the holes and pop them.

This is what I did and it worked, you may find variations on the theme, but the whole point is not to do a bodge-job.

Feel free to ask question or criticise, as in no way do I consider myself an ‘expert’ in any field, every days a school day, free speech is aloud in my house, as long as you’re not to offensive. Also, please excuse spelling and punctuation mistakes, but I think you'll get the drift.

Below is an extract from the FSM with regard to the fitment of the rivets.


View attachment 3214306

View attachment 3214416

This was so thorough and so clear! I really appreciate you taking the time to write it up! I have the new mouldings. Just need the rivets and the adhesive. I’ll grind down my harbor freight rivet gun and see if it will tuck into the channel without stressing the glass. Thank you!

 

[Smiles]

This was so thorough and so clear! I really appreciate you taking the time to write it up! I have the new mouldings. Just need the rivets and the adhesive. I’ll grind down my harbor freight rivet gun and see if it will tuck into the channel without stressing the glass. Thank you!

Your welcome,

Before you grind down your rivet gun I’ll send you pictures of what I did to mine. Hope everything works out for you, just remember theres no rush, the mouldings don't hold the screen in, so if you have to drive around for a while without the mouldings fitted it's no big deal, as long as it's not raining

Aslo, I forgot to mention, I was told by a windscreen fitter that the screen adhesive and silicone dont like each other, so just incase you were wondering, that's why I stress the point, not to use silicone, never tried the experiment myself, unfortunately, your going to use very little of the screen adhesive, and once opened the adhesive wont last, I'm talikg quite a few days not hours, so again, no immediate rush to use it.

Also again, if the weathers a bit on the chilly side in Atlanta when you want to stick the double sided tape part of the mouldings to the gutter, gentley warm the tape part of the moulding and the gutter with a hair dryer, not a heat gun it will be to aggressive, of course I am presuming you are working outside and not in a lovley heated garage. I dream of a big heated garage

Off subject a little but still on topic, and something to keep a ‘weather eye' out for.
Another place to check for water ingress is the rear high level third brake light, plenty of excellent posts on ‘mud’ about this subject.

 

[VasKav]

Really great intel everyone. Thank you!

Sorry to be lazy, but does anyone know where the AT fluid temp sensor is and what panel it runs into?

I’m definitely getting a lot of water down the passenger a-pillar. Windshield seems the likely culprit. Will also check roof rack.

Thanks again.

 

[DBULL]

I decided to check my sunroof drains for leaks and discovered that if I poured water into the front drains too fast I would have a drip under the dash. I believe that this was caused by the the catch pan being overfilled as when the sunroof is closed there is a seal that limits the amount of water entering the drains.The drain hoses showed no signs of blockage before and after being cleaned with a stiff piece of wire.

 

[Smiles]

I decided to check my sunroof drains for leaks and discovered that if I poured water into the front drains too fast I would have a drip under the dash. I believe that this was caused by the the catch pan being overfilled as when the sunroof is closed there is a seal that limits the amount of water entering the drains.The drain hoses showed no signs of blockage before and after being cleaned with a stiff piece of wire.

Well done