Why wont my GMC 3500hd bucket truck start?

[marielle]

it started but then shut off and won't start again. Both mechanics and electricians say that they can't find anything wrong with the truck.

 

[idontgivafork]

then you need a different mechanic.does it have murphy switchguages or a sentry system?very important, youll have to reset the sentry,or hold the button on the murphys.