How To replace an 986 (and 996) Ignition Switch

[½cwt]

The ignition switch can fail in two general ways, either dodgy electrical thing happening, or you ignition key starts to get stuck when you try to take the key out.  Most videos and how to guides on this are for LHD cars, however in the RHD cars where the ignition, key barrel and steering log assembly is effectively inverted the access is different and is in fact harder to do from underneath the dash as is show for LHD cars.

The ignition switch up to model year 2003 is a VAG part 4A0 905 849B and for 2004 is 4B0 905 849 which are listed as these numbers in the Porsche parts catalogue.  For my fix I sourced an aftermarket item for about £38 form ECP as they had one and it was urgent.  They can be had from about £15 upwards.

Tools required - Torx T15 driver, PH2/crosshead screw driver, flat blade screwdriver, small 3mm tip flat blade screw driver like a spectacle marker's screwdriver or small electrical screwdriver.

For a RHD car the switch can be access easily through the top of the dash by removing the driver's side air vent section and a section of the vent ducting.  First put teh vent into the closed position, this stops the mechanism that controls the flap in the vent fouling on the dash as you remove and re-fit it.  The duct section of dash is held in by three screws (Torx T15), one in the recess of the headlamp switch and two down the door shut by the A pillar and fix to the pink captive nuts in the picture.  Remove the two in the A pillar then the headlamp switch removes by pulling, (mine did not have this screw in place which was good as I found pulling the switch out damned difficult, so I left it in place in the vent section. Once this vent section is removed, using a cross head screwdriver remover the section of ducting that the vent attaches to (blue arrow), the section across the bottom of the dash will probably fall out too when you do this.

 

From here you can see the two retaining screws (red arrows) for the switch which will have some red paint or thread lock on them as shows better below.  This is where accessing from above works for RHD, not going underneath as in LHD, although you will be working by touch and feel to line up the screw driver blade in the slot of the grub screw.

 

Remove the large round pink loom plug on the back of the switch, you can reach under the dash to access this whilst looking down from above, it takes a bit of waggling to start but eventually comes easily once it starts moving.  Loosen the two grub screws once the loom is unplugged, don't take them out fully unless you fancy spending more time getting them threaded back in... then slide the switch assembly out of the metal casting.  Once removed, take a note that the two ribs on the sides of the switch, these slot into place between two pairs of lugs that the grub screws are in.

Using a flat blade screw driver make sure the new switch is turned the the 0 position, fully anti-clockwise when looking at the slot in the top of the switch.  Connect the loom to the new switch, it is much easier to align correctly before refitting the switch (I know I tried the other way first and had to take the switch out again), then offer the switch and loom back into place ensuring the two plastic lugs slot between the two pairs of metal lugs.  Tighten up the two grub screws.  Test that the new switch starts the car and ejects the key correctly when you take it out. 

Replace the horizontal ducting and screw the duct that feeds the back of the vent back into place.  Re-fit the vent section into the dash taking care to ensure the screws line up correctly with the pink captive nuts (these can move when removing or refitting the vent section).  Job Done.

If the key still does not eject properly when you switch off, your next move is a replacement key barrel/steering lock assembly 996 347 017 07 which is an up issue used from 2004 onwards but is backward compatible on all Boxsters.  Frustratingly this also come with an ignition switch but at £250 or so is 10 times the possible basic fix parts cost....

 

 

[ATM]

On 7/16/2022 at 4:35 PM, ½cwt said:

small 3mm tip flat blade screw driver like a spectacle marker's screwdriver or small electrical screwdriver

Any tips on where I can source one of these please.  Mine is a bit long and I cant get it onto one of the screws.  Also the one I can get it onto wont budge or I am not man enough to twist it with enough force.  Ideally I'd like a correct sized attachment for my small socket set but maybe that's asking too much.

[½cwt]

I was able to get one of these on:

Halfords 6 piece Precision Screwdriver Set | Halfords UK

Make sure the tip is fully in as they could be quite easy to burr off I imagine, and then the nightmare begins...

Edited February 8, 2023 by ½cwt