[DarkAngel]

Ive had an G3 Varient in for repairs do that before. All youd have to do is put the selector off safe and it would go full auto on its own. Turned out to be a small cut in the red wiring leading to the switch assembly.

While normally youd think 1 cut isnt bad, since youd need 2 to trigger a short, remember the gearbox is made of metal and is a conductor in itself. This can bypass the trigger contacts.