Its possible that the low beam filimant is burnt out or if you have separate lamps for high and low, that could be it too.
You can lookup your vehicle below to see if you have separate high and low beam lamps - this may help - see sources and related links.
well i think its the relay cause if one works and the other doesnt cause when the magnetic field is activated in it it will make the throw switch to the other pole
burned out its two sided Depending what year you have some had separate fuses for each headlight function, check the fuses.
It's a Cadillac, what do you expect?
Low beam bulb is burnt out. Replace it.
You need to change the light bulb, the high and low beam on some vehicles are contained in a single bulb. or you could have a bad connection on just that one light
Possibly the high beam element for the passenger side is broken. There are two elements inside those lightbulbs, one for low beam, the other for high beam.
Replace your dimmer switch and this should fix your problem Or both bulbs could be bad
Check the bulb Check to see if you are getting power to the socket
Usually it will be either the dimmer switch or a connecter if the low beam works and highs don't.
most likely problem is that the low beam side of bulb or sealed beam is burned out replace with a new one
Try changing the bulb that doesn't have the low beam. Check at your local auto parts store for the correct bulb.
84 should be mounted on the drivers side floor