The headlights on your 1990 4Runner don't turn on when the vehicle is started could this be fuse related everything else works fine Is there a main fuse that controls both headlights?
I dont think that the 1990 4Runner had daytime running lights so
you would have to turn them on yourself. Otherwise the headlights
each have their own fuse and a relay in the engine compartment, if
these are not bad then it may be the switch.