1978 m880 lights

[Creamoz1]

All the lights worked prior to my brother playing with the blackout switch. Now none off the regular lights work, head, tail, brake. Have tried every position on the BO switch with no luck. Any ideas? Thanks

 

[NDT]

He broke it. It’s 40 years old.

 

[Bob H]

Service drive location of the upper right lever
& left lever should be on panel
Fuse box should be the next stop.
Have had the 3 way switches go out on me before.
and 76 & 77 were the only model years of the M880 series trucks