quote:

---

Fiero OSG:
Info - 87-88 models

The 1987-1988 Fieros use a new headlight system, which is also used in 1987 and later Firebirds. This system has two motors and an electronic module which controls their operation. Here's how it works:

There are only two wires connected on each motor. Green(/black) and grey(black), and they connect to the output (4-pin connector) on the headlight control module. The other connector (5-pin) on the module is the inputs. The two red wires are the continuous power from the battery through two fusible links, as in the 84-86 system. The white and yellow wires from the headlight switch are also the same, as is the ground.

Everything on this system is done inside that little electronic control module. When the headlight switch is on, it trys to run the headlight motors in the up direction. When it is off, it tries to run them in the down position. Rather than having seperate wires for each (and ground), as the previous system did, this one reverses the flow of current across the wires to turn the motor in the opposite direction. Also, rather than having an internal limit switch inside the motor, the control module actually senses the current being used by the headlights. When there is a sudden rise in current draw, as happens when the motors can no longer turn, the module shuts off the power to the motors.

Internally, the main difference between the new motors and the old ones (other than the fact that the current sensing mechanism is now located in the control module rather than the motor), is that the new ones are designed so that rather than stripping out the gears that drive the motor, they have a bushing which will break. They are bolted together, rather than riveted like the older ones, so that this bushing can be easily replaced.

---