Horn, fan running after rain (1 Viewer)

[LCtygrys]

1998 LC bone stock
I was woken up during the night by the alarm going off during a rain storm. Car was outside. The only way to shut it off was to pull the horn fuse. I let it all dry out and it's been fine until another rain last night and the horn started beeping again and I noticed the fan was running and some of the lights were on on the dash. Key was in my hand. Where to start?
Thanks!

 

[nissanh]

Could be water entering into the horn and fan relays. It could also be a clogged sunroof drain that drains water into the fuse box located on the driver side kick panel. Remove the fuse cover and inspect the inside. It has to be dry. Also inspect under the carpet as any water there could lead to corrosion down the road.

Finally, clean the front sunroof drains. The drains are located towards the front of the sunroof (open it to inspect). You can use a string/line from a grass trimmer/edger to push down the derbies stuck inside the drain tube.

 

[LCtygrys]

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[Spike555]

This is easy, I chased this exact same gremlin for a year, it is a clogged sunroof drain, passenger side.
Drain overflows, water runs down outside of drain tube, drips onto electrics behind passenger kick panel and shorts them out.

Open sunroof, pour water down drain, you'll see where it's dripping from.

I was ready to set my truck on fire and sell it for scrap until I found the problem.

 

[Spike555]

I replied to your other thread of the same name with the fix.

 

[LCtygrys]

I replied to your other thread of the same name with the fix.

Thanks , sorry f rthe double post

 

[LCtygrys]

Ok first of all thanks so much for the quick helpful replies.
I ran some .095 trimmer string down both sides until it stopped. I then shot compressed air down both tubes. Drivers side went straight through but passenger side would only drop. There is no obvious orfice for the water to come out at the bottom and it just comes out through the seams in the sheet metal. That said, it was dripping out slowly along most of the length of the car on the pass. side. I drilled a tiny hole at the lowest spot and it drained for 5 minutes straight. I'm hoping now it has a chance to dry out completely. I'll update as we go. Thank you all again.

 

[Spike555]

My driverside rocker panel sunroof drains were clogged and it caused a rust hole just infront of the rear tire.
I would repeat the pouring water down the sunroof drain until it drained as fast as the driverside.
If it is partially clogged it will be easier to clog next time.
I have heard that pouring a can of Coke down the drain and letting it sit for 10min or so and then flushing with clean water works pretty well.

 

[LCtygrys]

Hi just an update on this. After drilling a small hole in the bottom of the area where the water was trying to drip out and seeing a large quantity of water flow out and then letting it dry out in the sun for a day the car has been fine...until last night. Rain early in the afternoon eventually found its way into the electronics again and woke up the neighborhood with the horn blaring again. After pulling the horn fuse I noticed that some of the relays in the fuse box were still chattering away so I disconnected the battery for the rest of the day and when reconnected it seemed ok. Later on the chattering started again as well as the headlights coming on. I have disconnected the battery again until I figure this out.
Two questions:
1) where / what is the common denominator for all these electrical components and
2) where is the water supposed to flow out of the sunroof drain tubes? I can't find the hole in the bottom under the rocker panel/ floor area and it just seems to drip out through the ends and weld seams

I pushed the weed trimmer line down as far as I could until it stopped but it never showed up anywhere down below.

help...

 

[jerryb]

the drain IS the pinch welds, there are no round holes. This is from a different roof drain post. Water in Rocker Panels & Passenger Floor from Sunroof?

 

[Julian Stead]

I have had this, mine was from around the windscreen after it was removed. You can take the A pillar trim off and see where the water is entering, also the pipe from the sunroof is visible. My leak was small, but the way the ECU's are placed the water just tracks down the wiring harness and straight into them. My leak was going into the left A pillar and with the exact same symptoms I would concentrate there first.

 

[Spike555]

Hi just an update on this. After drilling a small hole in the bottom of the area where the water was trying to drip out and seeing a large quantity of water flow out and then letting it dry out in the sun for a day the car has been fine...until last night. Rain early in the afternoon eventually found its way into the electronics again and woke up the neighborhood with the horn blaring again. After pulling the horn fuse I noticed that some of the relays in the fuse box were still chattering away so I disconnected the battery for the rest of the day and when reconnected it seemed ok. Later on the chattering started again as well as the headlights coming on. I have disconnected the battery again until I figure this out.
Two questions:
1) where / what is the common denominator for all these electrical components and
2) where is the water supposed to flow out of the sunroof drain tubes? I can't find the hole in the bottom under the rocker panel/ floor area and it just seems to drip out through the ends and weld seams

I pushed the weed trimmer line down as far as I could until it stopped but it never showed up anywhere down below.

help...

Your sunroof drains are clogged, water is dripping onto the electrics behind the kick panels.
Weed wacker line will NOT clear the clog, you need to use compressed air. You can also try Coke a Cola, the acid in it is supposed to eat away the clog, I used compressed air on mine.
A few quick burts with a air nozzle stuck in the top of the drain tube past where it fasteners to the collector in the sunroof pan, then I flushed with water.
Problem solved. Now I rise with water ever 6mo to keep the drains clear.

No need to unhook the battery, just do not lock the truck and turn the HVAC system off before shutting off the ignition.
Once it is all dried out it'll be fine.

 

[LCtygrys]

This is very good info. I did shoot a lot of compressed air down from the top but did not have a really good seal so it wasn't as good as it could be. Now that I know where it is supposed to come out I'll snake it from the bottom too. This is really irresponsible design!
Is the ECU on the passenger or driver's side? Thanks guys!

 

[Spike555]

You cannot snake it from the bottom.
There are many computers, both passenger and drivers footwell. Behind the kick panels.

I did not have a good seal either when using compressed air, I just did quick burst's. Then poured water down, 20oz pop bottle filled with water, both sides. The rears too.
Then called it good.

You can also seal the sunroof shut with marine grade silicone and just never open it again. I had to do that on my Land Rover.