Interior Light Delay Relay. Porsche 928 1978–95 › 92861822501

Genuine Porsche interior light delay relay 92861822501 for selected Porsche 928 models from the 1978–1995 model family. It manages the timed switching of the factory cabin courtesy lights.

Fits

• Porsche 928 – selected models
  928 (1978–1995)

Check fitment for your specific vehicle (model, year, engine) before ordering.

What This Product Does

This relay keeps the interior lamps illuminated for the specified delay after the triggering signal changes, then switches the circuit off. It is intended to retain the original operation of the Porsche 928 courtesy-light system.

Functions

• Manages the interior courtesy-light circuit
• Provides the factory timed lighting function
• Responds to signals from the associated interior-light controls
• Switches the cabin lamps off after the delay period

Technical Details

• Product type: interior light delay relay
• Brand: Genuine Porsche
• Part number: 92861822501
• Application: Porsche 928
• Relay plate position/code: XXI
• Electrical connections, fuse rating and related wiring must remain to factory specification

Symptoms of Fault

• Courtesy lamps do not illuminate when expected
• Interior lights remain on after the normal delay
• Cabin lighting turns off immediately rather than after the timed period
• Intermittent operation as the relay or fuse panel warms
• The relay operates audibly, but the lighting circuit does not respond
• Heat, corrosion or poor contact is visible around the relay terminals

Why Replacement Matters

Ageing or high-resistance internal contacts may produce inconsistent lighting operation even if the relay can still be heard clicking. Replacing a confirmed faulty relay helps reinstate the intended timing and switching while maintaining the original Porsche electrical arrangement. Before replacement, inspect the fuse, relay socket, terminals, earth points, door or hatch switches and connected wiring.

FAQs

• Can the relay click and still be defective? Yes. The coil may energise while worn or resistive contacts fail to pass current reliably.
• What should be checked before fitting another relay? Inspect the specified fuse, relay seating, socket condition, earth connections, switches and wiring for corrosion, looseness or heat damage.
• Can suitability be established from appearance? No. Confirm part number 92861822501 against the vehicle details before fitting.
• Should a higher-rated fuse be used if the original keeps blowing? No. Retain the specified rating and diagnose the short circuit, overload or wiring fault.
• Why might the cabin lamps remain illuminated? Possible causes include the relay, a door or hatch switch, an earth fault, damaged wiring or incorrect lamp connections.