Will the neutral safety switch keep my 1995 gmc yukon from start

check your fuses in the engine compartment theres a 10amp yellow color if burnt that's your problem

Yes, that's one possibility. Could be a bad starter. Could also be a weak battery. First either charge your battery or test it with a volt meter. Once battery is charged, have someone hold the key to the ON position like they're starting the vehicle. As they hold the key, rap on the starter with a hammer. It should crank over. If not, you are probably looking a a bad neutral safety switch.