Jaguar XJ6 350 3.0 litre auto 2003 100000 miles.

Having been parked in torrential rain, all kinds of warning lights came on, the gearbox started to act up and the speedo stopped working. The faults cleared up once it dried out but it took several days. They have also returned intermittently when it has been raining heavily.

There must be a common connector or something where water is affecting it, but I don't know where it could be.

 

Check the drain under the cabin filter