Where is the neutral safety switch on a 1990 ford probe?

The neutral safety switch on a 1990 Ford Probe is located on the transmission. It's usually a small switch mounted on the side of the transmission case, near where the shift linkage connects. You'll likely need to get under the car to see it clearly. Because of its location and the variations between automatic and manual transmissions, a precise location is difficult without knowing your specific transmission type (automatic or manual). A repair manual specific to your 1990 Ford Probe would be the best resource for pinpointing its exact location.