The problem you're experiencing is likely not a sensor issue, but rather one of these:
* The hazard light switch itself: This is the most common culprit. It's located on the center console, usually near the steering wheel. It could be faulty, or there might be a wiring problem to the switch.
* The hazard light flasher: This is a small electronic component that makes the lights flash. It's usually located under the dash, often near the fuse box. A bad flasher will prevent the lights from flashing.
* Wiring: A break or short in the wiring harness to the hazard light switch or the flasher can also prevent the hazards from working.
* Fuses: Check the fuse box for blown fuses related to the hazard lights.
To troubleshoot, start by checking the fuses and then visually inspect the hazard light switch itself. If these checks don't reveal the problem, you'll need a wiring diagram for your specific 1994 Chrysler New Yorker to trace the circuit and pinpoint the fault. A repair manual will be helpful here.