ProStreetDriver

Video tutorial on how to refurbish the BMW E39 ignition switch. This ignition switch is also found on a BMW E38 as well, but this maybe a similar procedure on other BMW models. This tutorial is intended to rebuild the existing ignition switch rather than purchasing a new or used one. A new replacement can be somewhat expensive and a used ignition switch may also have issues. Be sure to test the switch before putting it back into place as this ensure everything is working correctly. This particular tutorial was done on a 1997 BMW 540i.

Tools/Supplies Needed:
-small standard/flat screwdriver
-aluminum oxide sandpaper
-paper/cardboard
-electrical contact cleaner

Procedure:
-work in an area you do not risk the chance of losing any of the small components
-using a small standard screwdriver, split the case open
-the grey portion or top portion of the case must be pulled straight up, as the spring contacts sit in dividers inside the case
-now remove the round faceplate
-remove the rotation portion which controls the opening and closing of the contacts
-remove the small contact and spring from the rear of the assembly which activates the "key in ignition" warning light
-wiggle each of the contacts to determine if there is resistance or grabbing in the contact
-using aluminum oxide sandpaper (only use this form of sandpaper or an electrical safe sandpaper as it doesn't leave any dust/residue behind which could cause issues), fold it so there is abrasive materials on both sides
-spread the contact open, slip the sandpaper between the contact, close the contact, then move the sandpaper back and forth
-sand until satisfied and there is no more resistance or grabbing in the contact when wiggled
-do this for each of the contacts
-some maybe worse than others
-the "key in ignition warning light switch can be clean with either paper or cardboard
-once done, using electrical contact cleaner to spray/wash each of the contacts
be sure to use electrical contact cleaner in a well ventilated area
-allow the switch to dry
-you can test the switch with a multimeter to ensure everything is working correctly for reassembly
-reassemble in reverse of disassembly