John,
There is a wear sensor wire assembly for each of the four wheels. Any one broken will keep the light lit. I just went through checking My 93 LS400 and two were shot. The jerk replacing the rear pads mixed up left and right side, so the sensor wires ended up on top instead of the bottom of the pads. The retaining
clips therefore did not hold the wires and they broke lose. You can either short the two wires together and live without the sensors or spend I believe the $90.00 the dealers want for a new sensor wire.
good luck
