stalling 300tdi

I have a 1995 (n reg) 300tdi and for the last few days its started to stall. it does not splutter, just cuts out. after locking and un-locking the car for a few minutes it will start again and runs ok.
could a faulty stop solenoid cause this.
are stop solenoids easy to fit and where do you fit them

thanks for any info

after a bit of investigation it is a good chance it is a spider fault. going to take it out (if its fitted) and solder joints. if this fails ill put a live to the stop solenoid switch

just go to your local landy main stealers and get a bypass plug cost ya about £7

stripped out the dash and took the spider out this morning. looked on back of the circuit board and the the 2 large soldered joints had cracked. all soldered and dash back in now, now have to wait to see if it stalls again, if it does ill go to the dealers and get the bypass plug.
hardest part of the job was getting the digital clock and the coin holder out