100 series 2001 lx470 wipers randomly turn on by themselves

[msigm44]

So my LX will randomly turn on the wipers by itself. This issue appears to be totally random. Im leaning towards something being shorted somewhere. Has anyone experienced a similar issue? I desperately need to get this resolved as its super annoying and embarrassing when my rig decides to act possessed in public. I guess I need to know where the wiper motor wiring runs and what other circuits may tie into it. Does anyone have a ETM for the LX?

 

[riffman12]

that's a weird one

Not sure where the fuse is for wipers, but I have heard of leaky windshields letting water down the drivers a pillar down to the junction in drivers foot well by the dead pedal.

Maybe look around that box for signs of corrosion

 

[msigm44]

will do! in the past I have pulled the wiper fuse to remedy the problem. April is the wet season for NC so i need to fix it right sooner than later

 

[msigm44]

bump! really need an etm ot something. thanks in advance

 

[UltTrail runner]

Is the wiper set at auto position? It could be the rain sensor. My 05’s wiper was wiping like crazy when it rains. I disabled the rain sensor through tech stream.

 

[msigm44]

I have an 01 Im not sure that mine has the auto wipers. Ill double check when I go on lunch break. Hopefully its something simple like a rain sensor.

 

[msigm44]

Hate to revive an old thread but I am still trying to solve this issue. It hasn't happened since I last posted. I took my rig into a drive in car wash and the issue once again presented itself. I couldn't shut off my wipers. I dont see a setting for auto on my wiper stalk so I don't believe I have that feature

 

[CloudCity]

Sounds like water ingress. Either via poor windshield replacement of possibly clogged sunroof drains routing water elsewhere. Look under the dash for any signs of water and trace to source if possible.

 

[ruggedrudgate]

Did you ever figure this out? Mine will turn on randomly, I just pull the motor plug to stop it, but it will happen again when I plug it back in after an hour or so. Also I am unable to pull the wiper lever towards the driver to work, I have to spin the tip and it sprays oth front and back windows without activating the wipers.

 

[CloudCity]

Did you ever figure this out? Mine will turn on randomly, I just pull the motor plug to stop it, but it will happen again when I plug it back in after an hour or so. Also I am unable to pull the wiper lever towards the driver to work, I have to spin the tip and it sprays oth front and back windows without activating the wipers.

If you think this could be an error w the rain sensor, located near the rear view mirror, you can pop the cover off and unplug the sensor and it will revert to normal stalk operation. Easy enough to try and no cost.

 

[Flipped Bezel]

Mine will act silly sometimes on auto when bugs and/or debris foul up my windshield and trick the rain sensor into turning the wipers on.

 

[joshAUST]

Hi.
As others have suggested, possible water getting into one of the ECUs in the footwells causing intermittent issues?
I've had several issues relating to that, but I must admit, not to do with the wipers, so far.

However, in my case it seems to be caused by water ingress where the roof rack bolts are located.
On my UZJ100R, I've had water ingress from the roof rack bolt holes running down the side front windscreen sill and pouring into both the driver and passenger side, right past, and probably at times, over and into those ECUs.

Do you get any liquid ingress or damp spots near the side wall on either the drivers or passenger side carpets?
Mine did - I found where the bolts for the roof racks attached to be badly rusted, and the rubbers perished.
Its a really bad design to have the bolts located down in the channel where water will collect.

I've come back, after being at work all day, to find the car battery completely dead.
As I was trying to diagnose it, a passer by remarked that they had seen the hazard lights on my car on.

Somehow the water had got into the relevant ECU and caused the hazard lights to activate, all day, and drained the battery.
It may be worth checking out.
As others have said, if the windscreen has ever been replaced, that also could be a potential cause of water getting into the same areas.

 

[BillW]

Most likely water leaking into ecu connection or junction block in dash wiring harness. Driver side foot wheel/ a-pillar area. Leak possibly sunroof drain or windshield.

 

[ruggedrudgate]

Hi.
As others have suggested, possible water getting into one of the ECUs in the footwells causing intermittent issues?
I've had several issues relating to that, but I must admit, not to do with the wipers, so far.

However, in my case it seems to be caused by water ingress where the roof rack bolts are located.
On my UZJ100R, I've had water ingress from the roof rack bolt holes running down the side front windscreen sill and pouring into both the driver and passenger side, right past, and probably at times, over and into those ECUs.

Do you get any liquid ingress or damp spots near the side wall on either the drivers or passenger side carpets?
Mine did - I found where the bolts for the roof racks attached to be badly rusted, and the rubbers perished.
Its a really bad design to have the bolts located down in the channel where water will collect.

I've come back, after being at work all day, to find the car battery completely dead.
As I was trying to diagnose it, a passer by remarked that they had seen the hazard lights on my car on.

Somehow the water had got into the relevant ECU and caused the hazard lights to activate, all day, and drained the battery.
It may be worth checking out.
As others have said, if the windscreen has ever been replaced, that also could be a potential cause of water getting into the same areas.

That would actually make a lot of sense. I pulled the original roof rack off to put my pioneer rack on and there were zero seals or sealant around the bolts. Did pull the ECU plugs and dry them out? Or let them dry over time?

 

[joshAUST]

That would actually make a lot of sense. I pulled the original roof rack off to put my pioneer rack on and there were zero seals or sealant around the bolts. Did pull the ECU plugs and dry them out? Or let them dry over time?

The roof rack is meant to have a rectangular piece of rubber with two holes for the bolts to go through, so when you do up the bolts, it should make a watertight seal, assuming there's no or only a little rust.
.
If the rubber is not there, then I'd almost guarantee that water is getting in there.

Mine has a lot of rust, and that has made it hard to get it fully watertight, so I still get some water in.
I couldn't find the actual rubber parts available, I ended up using black selastic - a silicone compound, which probably isn't the best way, as it will make it difficult if I ever need to remove the roof racks.

My car has a rubber floor interior, so no carpet to worry about.
And when liquid did get in there and onto the ECU, by the time I got back to the car, the hazard lights being on all day had flattened the battery.
I jump started it, without drying any component, and it started.
One other time, a few weeks later, I did see the hazards come on, again after rain.
I find parking uphill reduces the issues, as I guess any leaks drain towards the back of the car.
If you hear any sloshing of water, and its not in the doors, you may want to check the drain plugs that are in the rear wheel wells, on the front side.
After very heavy rain, I heard it sloshing around, then happened to notice those black drain plugs, and several litres came out of it.
Good luck with yours.

 

[msigm44]

just an update to what the cause and fix was.

my truck was involved in a minor front end collision prior to my ownership. the ensuing damage destroyed the front left fender, bumper cover, L head lamp, and the washer fluid reservoir. I bought the truck with only the headlamps and fender replaced. I thoroughly inspected the wiring for the wiper and washer system with no signs of shorting or breakages in the circuit. with all that being said, the washer system was absent from the vehicle with the exposed electrical plug to the washer motor. Mind you, this issue only presented itself when it was raining in below freezing temps here in NC. This led me to believe that the surface tension of rain water on the washer motor plug was shorting pins to activate the washer system over and over again. I replaced the entirety of the washer system and restored my wiper washers successfully. After this repair I have never had the issue again and I am in the exact same conditions at the exact same time of year. The lesson to be had here is that these trucks have electrical components that are extra sensitive to water ingress and can contribute to some wild electrical gremlins. Inspect all electrical plugs and panels for failed weather seals or signs of corrosion. I drove with this issue for a year straight and have finally put it to rest. i hope this can help others who are having weird electrical issues

 

[ruggedrudgate]

Update to my wiper issues. It was a “broken” wire about 10 inches into the harness. Looks like the wire cracked, and water/mag chloride got in and corroded it to the point of it turning into a green powder. All had been returned to normal.

 

[salsaredpearl]

just an update to what the cause and fix was.

my truck was involved in a minor front end collision prior to my ownership. the ensuing damage destroyed the front left fender, bumper cover, L head lamp, and the washer fluid reservoir. I bought the truck with only the headlamps and fender replaced. I thoroughly inspected the wiring for the wiper and washer system with no signs of shorting or breakages in the circuit. with all that being said, the washer system was absent from the vehicle with the exposed electrical plug to the washer motor. Mind you, this issue only presented itself when it was raining in below freezing temps here in NC. This led me to believe that the surface tension of rain water on the washer motor plug was shorting pins to activate the washer system over and over again. I replaced the entirety of the washer system and restored my wiper washers successfully. After this repair I have never had the issue again and I am in the exact same conditions at the exact same time of year. The lesson to be had here is that these trucks have electrical components that are extra sensitive to water ingress and can contribute to some wild electrical gremlins. Inspect all electrical plugs and panels for failed weather seals or signs of corrosion. I drove with this issue for a year straight and have finally put it to rest. i hope this can help others who are having weird electrical issues

Wow my truck developed this exact problem for the first time ever last night while driving on the highway in a bad snow storm. Interestingly my truck was hit in the driver fender/bumper last year and these were replaced but I have yet to reinstall the washer fluid reservoir and fender liner that are sitting in my shed.

I will get all this re installed and inspect wiring and report back if it resolves the issue! Thanks for posting, if I wouldn’t have found this I’d have been tearing into the wiper motor like other threads suggest.

Only dealt with it for about 2hr drive last night but honestly impressive just how annoying this problem is when it’s happening.