Rain effecting central locking and hazzards

[AndysVerso]

Hi, I purchased a 2008 petrol 1.8 corolla verso vvt-i a couple of months ago and have since found that it has dreaded electrical gremlins and I've been tearing my hair out trying to get to the bottom of it.

Unfortunately it seems when ever it rains the central locking goes crazy and repeatedly locks it's self over and over every second or so whenever the key is not slotted into the dash with the ignition on. If you turn the engine off and remove the key before you get chance to open the door it will have locked it's self solid and you can't even manually unlock it as the manual unlock button on all doors just bounces back to locked (yes the Mrs got stuck in the car because I forgot to tell her if it's raining the only way out is too open the door before you turn engine off and remove the key) 😬🤦🏻‍♂️ This also causes the red light on the key fob to flash continuously even when it is out of range of the car 🤔 (I changed the Battery just incase but it did nothing different) it also causes the hazard lights to keep repeatedly flashing. This will all continue to happen until the rain has stopped and the car has thoroughly dried up and then it all returns to normal again and works perfectly! so it seems it is definitely caused by water.

I have taken both front door cards off and checked everything is intact and dry, the passenger side one was missing the plastic liner that sticks to the metal frame work so I replaced this hoping this could be it and water was getting into the door/lock but it wasn't and the problem still continues. I checked the door and boot seals and rubbers on the hinges where cables all come through each door inc boot and all are intact and look healthy. There is no signs of damp or wet inside the car or around any of the fuse box areas that I can see or feel.

I even put a hosepipe over the car in stages to see if I could recreate the fault and identify the area responsible but no matter how much water I poor all over the car it does not cause the problem, however the moment it has a slight rain shower and the car is just sat on the drive doing nothing it starts.

I tried to remove the number 43 central locking fuse from behind glove box to see if this would temporarily stop it until I find where the fault is but all this did was literally stop the doors locking as you'd expect 😂 the key fob and hazard lights still flash through the night like a Christmas tree. When the locks/lights are going mad you can hear a relay or something clicking in sync from around the fusebox area behind the glove box. I think it maybe from the larger silver electronic box with lots of cables coming from it? This might just be the normal noise it is supposed to make when lights or lock buttons is pushed though I don't know🤷🏻‍♂️

Would anybody be able to point me in the right direction to where the fault may lie or at what point water could get in and cause these type of symptoms? 

My poor neighbours can't take much more of the flashing lights all night long 😆 

Many thanks 

Andy

[AndysVerso]

Still doing it. Any suggestions or maybe someone could point me to an area where I could test something?

I have found that it you take the fob Battery out it stops the car from locking when the car is wet? this makes no sense to me because the fob is dry and can be totally out of range from the car but still be flashing red when the car gets wet.

Only when the car thoroughly drys out from a rain storm does it all start to function properly again.

Could the remote central locking module be getting wet? Where is this located on a 2008 corolla verso?

Regards Andy