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Clark's Garage944 · 924 · 968 · Turbo
ReferenceWorkshop Manual · Group 94

944 Exterior Lights & Headlights — Bulbs, Aim & Concealed-Headlight Service

Factory service data for the 944's exterior lighting — greasing the concealed (pop-up) headlight linkage, removing and refitting the headlight beam-control actuators, checking the electric beam-control voltages, and aiming the main headlights to the factory beam-drop figures. The '88-on cars carry an in-cabin load-compensation switch; the aiming targets change with its position.

Difficulty: Moderate5 min readApplies to: 944

Factory service data for the 944's exterior lighting. This page covers the jobs that keep the concealed (pop-up) headlights and the main-beam aim in order: greasing the linkage, handling the electric beam-control system fitted from the 1988 model year, and setting the aim to the factory beam-drop targets. For the theory and repair of the pop-up headlight motor circuit itself — the motor, relay and rotary switch — see Headlight Motor Circuit — Operation and Repair. The aiming and checking values are voltages and beam-drop distances rather than torques or capacities.

Bulb and lamp wattages

The exterior bulb sizes below are the common fitment for the 944. The biggest split is the main headlight: Rest-of-World cars carry a replaceable H4 halogen (one bulb doing both high and low beam), while US-market cars were delivered with a round sealed-beam unit instead. Several rear functions that look like one dual-filament bulb are in fact separate single-filament bulbs in their own sockets (the tail and the brake light especially).

PositionBulbWattage
Main headlight, high/low beam — RoWH460/55 W
Main headlight — USA (sealed beam)H6024 (7-inch round sealed beam)65/35 W
Front fog light (optional)H355 W
Front turn signal + parking light (combined)P21/5W (1157)21/5 W
Front side-marker — USA onlyW5W (194)5 W
Tail / running light (rear)R5W5 W
Brake / stop light (rear)P21W (1156)21 W
Rear turn signalP21W (1156)21 W
Reversing (back-up) lightP21W (1156)21 W
Rear fog light — RoW onlyP21W21 W
Rear side-marker — USA onlyW5W (194)5 W
Licence-plate lightC5W festoon / T4W bayonet4–5 W
High-mount (third) brake lightsmall halogen / P21WUS cars from 1986; Cabriolet

Source note: unlike the service procedures below, this bulb list is not reproduced from the Group 94 workshop-manual section — it is compiled from Porsche parts-vendor fitment data and the owner's-manual bulb chart. Fitment varies by market and model year, so check against your own car before ordering. A few positions are less certain: the licence-plate bulb is quoted as either a festoon (C5W) or a small bayonet (T4W) depending on the source, and the high-mount brake light applies only to US-market cars (from 1986) and the Cabriolet. The US sealed-beam figures are the sealed-beam unit's rating; cars converted to the RoW H4 headlight use the 60/55 W H4 bulb instead.

Lubricating the concealed-headlight linkage

Grease the linkage of the concealed (pop-up) headlights with a general-purpose (multi-purpose) grease whenever the car is serviced, and again after the engine bay is washed. Washing strips the old grease off the exposed pivots, so re-greasing after a wash keeps the pop-up mechanism moving freely.

Beam-control actuators — remove and install

From the 1988 model year the headlights carry an electric beam-control (headlight-levelling) system. Its principal parts are the in-cabin control switch — a potentiometer — and two actuators, one behind each headlight, mounted on the headlight frames.

To remove an actuator:

  1. Disconnect the cable plug from the actuator.
  2. Unplug the cable connector from the headlight.
  3. Remove the headlight.
  4. Disengage the actuator from the headlight frame with Special Tool 9287. Push the tool over the plastic part to squeeze the detent lugs together.
  5. Turn the actuator anticlockwise through about 60° and withdraw it.

Refit in reverse order.

Checking the beam-control voltages

With the beam-control system connected and a voltmeter, you can confirm the switch and wiring are feeding the actuators correctly.

  1. Disconnect both plugs from the actuators.
  2. Switch on the lights.
  3. Measure the supply voltage between terminal 1 (+) and terminal 3 (−) — the reading should be battery voltage.
  4. Measure the control voltage between terminal 1 (+) and terminal 2 (−) as the switch is moved through its positions:
Switch positionVoltage at terminal 1 (+) / terminal 2 (−)
Position 0approx. 0 V
Position 12.0 V to 2.7 V
Position 22.6 V to 3.4 V

If no voltage reaches the actuators, check fuse 37 (944) or fuse 7 (924 S).

Note: the battery voltage read during this test must sit between 11 V and 13 V. If it is lower, recharge the battery before trusting the readings.

Aiming the main headlights

The main headlights are aimed with the beam-control switch in position 0.

  1. Switch on the lights.
  2. Aim the headlights with a headlight aiming device, with the car ready for the road: fuel tank full, the driver's seat loaded with one person or a weight of 75 kg165 lb, and the tyre pressures set to specification.

With the beam-control switch in each position, the main-beam centre should drop over a 10 m distance by:

Switch positionBeam drop over 10 m
Position 010 cm
Position 122 cm ± 1 cm
Position 225 cm ± 1 cm

The beam-control switch position is chosen for the vehicle load:

PositionLoad
01–2 occupants, no luggage
13–4 occupants, no luggage
21–4 occupants with luggage
Tags:headlightsexterior lightsbeam adjustmentheadlight aimingconcealed headlightsbeam controltechnical data

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