Yaris not starting in the rain

[TonyHSD]

+1 for water leak that cause the issue with Battery and non starter. 
Areas to check after rain before you try to start and drive are engine top part and particularly coils. Battery, fuse box, wiper arms gutter- this should be thoroughly clean from dirt and debris, leafs etc. Starter motor cables. Also can check drivers and passengers footwells.  
If all ok you can try something else. On cold engine cover with something that prevents water going over the engine, let it seat when raining but don’t forget to remove the cover before you start. Try and see what happens for the engine starts after been protected from water. 

[KennedyMC]

6 hours ago, TonyHSD said:

+1 for water leak that cause the issue with battery and non starter. 
Areas to check after rain before you try to start and drive are engine top part and particularly coils. Battery, fuse box, wiper arms gutter- this should be thoroughly clean from dirt and debris, leafs etc. Starter motor cables. Also can check drivers and passengers footwells.  
If all ok you can try something else. On cold engine cover with something that prevents water going over the engine, let it seat when raining but don’t forget to remove the cover before you start. Try and see what happens for the engine starts after been protected from water. 

Thanks Tony 

[TonyHSD]

1 hour ago, KennedyMC said:

Thanks Tony 

You are welcome. 

[FROSTYBALLS]

Moved to the Yaris forum.

[MikeSh]

Most people are focusing on the ignition but as one other has said the failure to even unlock indicates something more fundamental - in addition if nothing else.

As the Battery has been replaced it's perhaps a main connection problem. A loose connection would explain most of this and has caused grief on many cars over many decades. So check all the heavy terminations between the Battery and car, particularly negative to body and engine as those are often exposed and degrade.

[KennedyMC]

6 hours ago, MikeSh said:

Most people are focusing on the ignition but as one other has said the failure to even unlock indicates something more fundamental - in addition if nothing else.

As the battery has been replaced it's perhaps a main connection problem. A loose connection would explain most of this and has caused grief on many cars over many decades. So check all the heavy terminations between the battery and car, particularly negative to body and engine as those are often exposed and degrade.

Thanks Mike, I think the mechanics have tried this but I will have another look

[bathtub tom]

How long have you had the car, and is this a new problem? Is there any evidence of accident damage repair?

[KennedyMC]

4 minutes ago, bathtub tom said:

How long have you had the car, and is this a new problem? Is there any evidence of accident damage repair?

I’ve had it 8 years and it’s 10 years old. The problem has been happening for over a year now and has been to different mechanics and sparks but has had no accidents or damage nor any other mechanical problems bar this one. 

[Biomecanoid]

Water is getting in places it should not or it could just be a ground issue. Get a nice thick wire and run from the negative pole of the Battery to an exposed screw in the engine compartment and see if something that simple fixes your issue.

 

If it does you should clean all your grounds as they must be dirty of corroded