That is what I was asking. You CANNOT change daytime brightness (headlights OFF). Your system is working fine.thank you you two reply.
no, i don't mean headlight. i can't change the dash light brightness.
when i pull out the headlight switch to first stop and second stop, the dash light brightness can be changed by turning the switch. only when i push this button all way in(means turn off all outside light like parking lights, headlight),
then i can't change dash light brightness. it stay at brightest mode. and you know what, today i take off the whole unit from the car, but the dash light still there ,why the dash light still on without this control unit?