oil pressure switch Genuine Porsche part 90161357101

The 901 613 503 20 is a dashboard-mounted mechanical or push-pull switch used in early Porsche 911 / 911S / 911L and 912 models (1960s era) to activate the front fog lights. It is often grouped with the rear-window heating and warning-light switches, depending on vehicle specification.

In use, pulling or pressing the switch completes the circuit for the fog lights, sending power (via fuse and relay) to the fog lamp units. The switch usually has an internal light (“light-pipe”) or indicator so you can tell when fog lights are active. 

• Porsche 911 65-68 + 911S, 912 USA version 911L with red lighting strip
• Porsche 911 1965-1968 2.0L / 912 SWB (F)
• Porsche 912E 4CYL 1976  

·         Even though the fog light switch is a relatively simple component, there are several reasons why it might need replacing:

·         Internal wear or contact failure. Over time, the internal contacts inside the switch can wear, corrode, or lose tension, leading to poor electrical contact. If that happens, the fog lights may not activate when the switch is engaged.

·         No illumination of the switch itself. On models where the switch includes a light-pipe or internal lamp so that you can see the switch position, failure of that internal illumination can make it harder to know whether the fog lights are on and may indicate internal switch failure.

·         Switch stuck or mechanically broken. The pull/knob mechanism may become sticky, stuck, or physically break, especially after decades of use, or due to heat/cockpit environment ageing. A switch that doesn’t move properly or won’t stay in the “on” position cannot reliably activate the fog lights.

·         Intermittent operation / flickering. Even if the switch appears to work, intermittent contact inside the switch might cause the fog lights to flicker, drop out, or not turn off properly.

·         Fuse or wiring feedback problems. In some cases, a failing switch can lead to blown fog-light fuses or feedback to wiring loops, especially if there is an internal short or poor contact. Replacing the switch may be required after troubleshooting electrical issues.

Diagram ref no 13