For my 1990 I grabbed a brake switch from a mid-90s Chrysler car. It is a black box with 6 wires coming out, and a threaded rod that fits through the bracket directly above the existing OEM switch. The plunger inside the threaded connection goes up against the brake pedal steel shaft, above the stock location. You need to use a meter and check which wires on the new awitch are pairs, and see which are normally open and normally closed with the brake peddle not pushed (so the plunger on the switch is pushed in). Use the open or closed connections to match the ones you remove from the OEM wiring, you could have three circuits: brake lights (normally open), cruise control disconnect, and converter unlock. Match the last two to the way the oem switches were set (normally open or closed). On the one I got, it had exactly the right mix of open and closed.