This feature enables the automatic closing of the windows and sunroof (or Cabriolet hood) to be overridden to ' vent ' your Porsche, i.e. to leave windows and sunroof (Cabriolet hood) open on Summer days. Switch the 'vent' switch down"..The ultrasonic protection is de-activated. All other Alarm System features remain armed, i.e. LEDs flash, fuel pump isolated. After disarming the Alarm System, the dashboard LED continues flashing warning that the 'vent' switch is down and the next System arming will be partial unless the switch is returned to neutral.

A spare DME relay is a must. A spare fan belt is advisable as are spare bulbs. Other than that it's unlikely that anything more complex will be repairable by the side of the road.

The electronics in a 964 consume power from the battery even though the ignition is not switched on or the car running. Components such as radios and alarms are renowned for demanding excessive currents as well as faults such as lights remaining on (check the luggage, glove box and engine lights) as well as the sampling fan behind the CCU. A common fault is the failure of the driver transistor for the sampling fan, resulting in the fan running continuously until the battery is flat.

80ma or less

The complication when upgrading from the flag mirrors to the aero, or teardrop, mirrors is the wiring. The flag mirrors have 5 wires, the teardrops have 6. Full details of the upgrade, including the wiring are shown in the article first published in 911 & Porsche World magazine in December 2002. A reprint of the article can be found here.

The PA2000 alarm, manufactured by Hamilton & Palmer specifically for fitment to Porsche vehicles, is a Thatcham Catagory 1 alarm which incorporates the factory fit Catagory 2 immobilisor. A full Operation Manual can be found here.