1990 Chrysler New Yorker Bright headlights dim or turn off

What do you mean by "until I hit the dimmer switch"? The bright lights come back on when you hit the switch or the low beams turn on and then you can flip the switch a second time to turn the brights on?

If you are physically hitting the switch to shake it, suspect overheated teminals and wires. It's best to replace the switch, then the overheated terminals can be cut out of the plastic connector body and replaced individually.

If you flip the dimmer switch once and the low beams turn on, then flip it again and the high beams work, suspect burned conacts inside the dimmer switch.

If the high beams go out, then when you flip the dimmer switch once and it takes a while before the low beams come back on, suspect the built-in circuit breaker in the headlight switch is tripping. It resets automatically when it cools down. The circuit breaker could be weak requiring replacement of the headlight switch, but non-standard bulbs could overload the switch too. Look for the wrong headlight bulbs or something added onto the circuit.

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