Engine wont stop!!

[PhilE]

I would be very grateful of any help. My 2001 Tuscan RR has delveloped a rather interesting fault. The engine wont stop after swithing off the key. I runs for about 30 seconds thenn I can hear a clicking noise from a relay somewhere and it stops. The same happens for the headlights and dash illumination. Ive tried all the fuses and relays in the footwell and these seem to be okay. Is there another relay hidden somewhere behind the dash that performs a major function. I will check and clean the earth strap to see if this helps. BTW, the lcd dash is virtually out. Does this mean a whole new unit?
Any feedback would be gratefully received.