Sorry don't understand how changing switch will help. The purpose of the switch is to prevent the engine from starting/running when no one is in the seat. Currently the ignition works if no one in seat or, even if, switch is disconnected i.e it is acting as if the switch is closed (except it is not running). I was wondering if there was a problem somewhere else in the circuitry that is causing the switch to be overwritten yet the engine fail to fire?
Sorry not getting back to you sooner. Will have to wait till tomorrow before I can check to see if a short is the problem.
Have done a continuity check on switch and leads. Switch is okay - appears to be working. There is no continuity between the separate (yellow and black) leads but there is continuity from the black(double) lead to ground. There is no grounding of the yellow lead. Does this signify anything to you?
Okay It's working -don't ask me how. Seat switch still doesn't work i.e. i can get out of seat and it still runs. The only thing I did was to operate the clutch/drive pedal so may have been a problem there with the cut out. Thanks for all your help.