Low beams for a 89 crown vic
If you pull the light switch to turn on the head lights, then there should be a dimer switch on the floor for your left foot.
I believe that the dimmer on that year was part of the combo switch with the turn signals, you just pulled back on the turn signal stalk to click them from low to high and back again. See pic.
It may be this combo switch, all I came up with was the dimmer on the floor. Never the less, it is one or the other.
Looking for a Used Crown Victoria in your area?
CarGurus has 1,234 nationwide Crown Victoria listings starting at $1,995.
Search Ford Crown Victoria Questions
Ford Crown Victoria Experts