Gen 2 headlight system

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Gen 2 headlight system is the second-generation pop-up headlight system used on the Pontiac Fiero.

The Gen 2 system was used on 1987 and 1988 Fieros. It replaced the earlier 1984-1986 first-generation system and uses a different control method, different motors, and a headlight control module.

Overview

All Fieros use retractable headlight doors, but the 1987-1988 cars use a later headlight system that differs significantly from the 1984-1986 system.

The Gen 2 system uses a central Headlight control module to control both headlight motors. This differs from the earlier Gen 1 system, which uses separate relays and earlier-style motors.

Applies to

The Gen 2 headlight system applies to:

Earlier Fieros use the Gen 1 headlight system unless they have been converted.

Major components

The Gen 2 headlight system includes:

How the system works

When the headlight switch is operated, the headlight control module receives the command and powers the headlight motors.

The module controls motor direction and stops motor operation when the doors reach the open or closed position. The Gen 2 motors and control module are designed differently from the earlier Gen 1 relay-based system.

Common symptoms

Common Gen 2 headlight problems include:

  • One headlight door does not open
  • One headlight door does not close
  • Both headlight doors do not move
  • Motor runs but door does not move
  • Motor keeps running
  • Door moves slowly
  • Door stops partway
  • Intermittent operation

Common causes

Common causes include:

  • Worn motor bushings
  • Worn motor gear
  • Failed headlight control module
  • Bad grounds
  • Damaged wiring
  • Poor connectors
  • Binding headlight door mechanism
  • Weak battery voltage
  • Previous-owner wiring changes

Diagnosis

Diagnosis should start by identifying whether the problem affects one side or both sides.

If only one headlight door has a problem, the fault may be in that motor, linkage, wiring, connector, or mechanical assembly.

If both headlight doors have a problem, the fault may be in the switch, module, power supply, ground, fuse, or shared wiring.

Basic checks include:

  1. Confirm the car uses the Gen 2 system.
  2. Check battery voltage.
  3. Check fuses and power supply.
  4. Inspect grounds and connectors.
  5. Check for mechanical binding.
  6. Determine whether one or both motors are affected.
  7. Inspect or test the headlight control module.
  8. Inspect the motor internals if power and ground are present.

Motor repair

Many Gen 2 motor problems are caused by worn internal parts. The motor may run without moving the headlight door if the internal gear or bushings have failed.

Related topics:

Control module

The headlight control module is a key part of the Gen 2 system. A failed module can cause one or both headlights to malfunction, depending on the failure.

Related topics:

Gen 1 and Gen 2 differences

The Gen 1 and Gen 2 systems are not the same.

The 1984-1986 Gen 1 system uses early motors and relays. The 1987-1988 Gen 2 system uses later motors and a control module.

Parts, wiring, diagnostics, and common failures differ between the two systems.

Related topics:

Conversions

Some earlier Fieros have been converted from the Gen 1 system to the Gen 2 system. A conversion may involve motors, wiring, module mounting, connectors, and related hardware.

Related topics:

Notes

The Gen 2 system is generally considered more modern and simpler to diagnose than the Gen 1 relay-based system, but age-related motor, wiring, and module problems are still common.

Always confirm which system is installed before following a diagnostic or repair procedure.

See also