355 headlight controller?

i'm having a problem with the headlights. seems the left side has decided to pop up but not back down. when the problem first started, i replaced a blown fuse/cleaned relay terminals to retore the up function but now, the lights will not go back down unless manually lowered or energizing relay, see below. as per owners man there is a controller somewhere in the car. does anyone know where this might be located? at this point, the headlight that operates shows pulsed power on the 86 ter. of the relay on both up and down whereas the other only shows pulsed power on the up. by energizing the 86 terminal, i can raise or lower the defective headlamp. this leads me to believe that whatever is supplying the pulse needs to be smacked around a bit. thanks for any help!!!