Motorcycle Repair: neutral light, triumph sprint sport, internal switches

Question
i have a 1997/8 triumph sprint sport 900triple     the problem i am having is that when the bike is cold the neutral light is on, but when the bike is warmed up the neutral light doesnt light up so the bike thinks it is in gear,so i cant leave the bike running with the side stand down any ideas. by the way new neutral switch has been fitted.

Answer
Hi Wilkie.
 which switch has been replaced?  The sidestand switch or the neutral switch inside the engine?

 If it's the one in the engine, then the problem is in the wiring or the sidestand switch.

 If it's the one for the sidestand then the problem is either the internal switch or the wiring.

 I am putting my money on the wiring having a short somewhere at or near the egine side of the circuit or the internal switch has gone bad (this is least likely of the 2), because the internal switches tend to be quite reliable.

 The sidestand switches tend to fail more often than not, but do not produce failure of the neutral light.  When the internal  switches fail, they tend to fail completely or be inconsistent as to when they fail.  This light failure is consistent as to when it is happening.

Start with the wiring and check each component of that circuit for a failure, bad connection or short.

Good luck.
FALCON