Toyota's have three bulbs in the taillight pod, Taillight, Turn signal, and brake light. If you are using a combo taillight it only has two circuits taillight and stop/turn signal. In order to get that to work you have to get a converter that takes it from three-wire plus ground to two-wire plus ground. On my 90 the white with a black stripe is the stoplight wire. I looked on the CD I have the 85 FSM on but it does not have any wiring schematics.