2005 s type auto diesel 2.7 after rain the warning light cones on and car goes into restricted mode it appears water is getting onto some electrical parts other wise car run well in the dry

 

1st thing to do is check your boot ASAP. Water can fill the boot to the point of damaging electrics.
This is a common fault on this model.
If its full of water start bailing and then seal the boot lid rubber strip and seal the rear light assys.

2nd thing to do is introduce yourself here:
https://www.jaguarforums.com/forum/n...-intro-must-5/

Welcome to the Jaguar forum !

 

+1 on the above !

 

+1 above but also check to see if water is running down in between wiper vowl and windscreen. Another common issue that plagues the S Types.

Simple way to check is open bonnet take a garden hose let water run down windscreen.

 

Both boot and windscreen are the prime contenders... +1 on both for me

 

 

You are welcome.