Land Rover Freelander clicking noise from front,

After some heavy rain, I had problem with the electrics, particularly the central locking and alarm. When driving for an hour or so noticed speedo and fuel gauge not working. They then started again but a clicking noise had started when the car stopped at lights etc. when the car was running normally no noise only when stopped. When I turned off the motor and just put the ignition back on the ticking persisted. Since then have had intermittent problems with the alarm. The noise sounds like two gears not meshing but just hitting each other's teeth, car runs normally, no starting problems and all lights etc are working. There is no obvious damp in fuses etc. ticking only occurs after running for about an hour. Before then it's normal.