[BMWCSRegistry] Lights out! (UPDATE)

[gary.jane]

Well, after some more poking around and further analysis, my lights are back!  Here are my recovery actions - file the solution for further reference, should this situation happen to you. Happy Holidays.


Gary Burke
1973 3.0 CS
+2240356+


I first contacted a local craigslist seller who was selling many E3 arts, to see if he was parting out an E3 that might have a working light switch.  Turns out he's a BMW nut who's also a metalsmith, welder, body work man and car painter with a HUGE shop annexed to his house.  He had a big bin full of BMW switches, so "come on over...".  I pulled my switch (just in case) and took it along with me.  My switch had a bit of oil mist gunk on the case, but the male spades all looked good and the female leads in the collective plug all were tight and looked clean also.

Upon getting to the seller's house, we dived into the box of switches, but were unable to find an exact match for my switch.  NOTE:  he had at least a dozen light switches from E3's and 2002's, and they all had the exact layout of the male spades on my switch, but all these non-E9 switches had male spades significantly smaller than my spades.  He even pulled the switch from an E24 hulk he has and we saw the same story as the E3 switches.  So, sad story short: 2002, E3 and E24 switches are close, but no cigars.

Back home and to the drawing board.  I used my multi-meter to test continuity between (amongst?) the spades on my switch.  I discovered that, on the first detent, the hot spade (red) fed four other spades (three of which feed ALL the non-functional lighting, listed below;and one of which had no female lead in the plug - I'll call this spade "unused"). On the second detent, the additional hot spade (green) fed the yellow/white spade, giving head light function, with all previous, first-detent functions holding constant - except that the unused spade now was dead.  I also learned that the rheostat (sp?) on both first and second detent, lit up two spades, one of which has a double gray/blue feed, the other a single gray/red lead.  Per my wiring diagram, the gray/blue wires are for the instrument lights, so the rheostat tie-in is logical. The gray-red/rheostat tie-in puzzled me at first, as I could not think of an additional use of continuously graduated light functioning in my coupe.  Upon a very close review of my wiring diagram again, I noticed some truncated gray-red wire references, all leading "to fog light".  

Here's what I think I have found:  Hans and Franz mis-wired the plug.  The gray-red lead should have been wired to the "unused" spade, thus allowing fog light function (should the car be equipped with fog lights) on the first, but NOT the second, detent. I believe it may be illegal in Europe (or parts of it), and/or some states in the US, to have fog lights operational when headlights are operational. What the envisioned use of the second, rheostat-controlled spade is, therefore, still in doubt. BUT, I wish I'd known all this before I wired in the illumination on my 3-gauge cluster. I could have merely used this spade!

So, with functioning continuity, I suspected that my switch was, indeed, still OK. Maybe it was experiencing non-functionality due to age/crud build-up internally (note: the switch is not hermetically sealed - there  is a large opening at the back - perhaps to allow rapid dissipation of heat around the rheostat)/dirty male and female connections.  I took Charlie's (of Hawaii) advice and shot the switch full of electrical contact cleaner, and also sprayed the spades and female receptacles.  Some black dripping did run out the opening on the switch, so it was a bit dirty internally.  I let everything dry over night and reinstalled the switch this morning. VOILA - all is well again, and I think I may even have increased illumination in my instruments.


----- Original Message ----- 
  From: gary.jane 
  To: coupegroup 
  Sent: Monday, December 17, 2007 2:28 PM
  Subject: Lights out!


  Well, Happy Holidays!

  I traveled about 10 miles from home to attend Thanksgiving dinner at a fellow BMW lover's home, and, upon leaving, and/or arriving home, I was so joyed to discover that the following lights were inoperable in my coupe:

  - side marker lights: left and right, front and back
  - tail lights: left and right
  - license plate lights
  - under-hood light
  - instrument cluster illumination
  - custom guage set illumination (lighting wired into stock cluster lighting)

  I have been laid up with a severe cold/sinus condition for some 7 weeks now, and today was the first chance I have had to even look at my coupe since Thanksgiving. Here's what I have verified as working:

  - head lights: high and low (low/high)
  - tail lights: left and right
  - directional parking lights (operated by turn signal stalk when car is parked - European delivery option): front and rear 
  - back-up lights: left and right
  - trunk light
  - brake lights: left, center (I added one to my package shelf), and right
  - hazard warning s/w (all 4 turn signal lights)
  - horns
  - instrument idiot lights
  - fuel guage
  - water temp guage
  - custom guage cluster guages: oil pressure, water temp, ammeter
  - heater blower fan
  - wipers: intermittent, low, high
  - wiper washers
  - cigar lighter
  - radio
  - interior courtesy light

  The coupe starts and runs per normal, which is very well now, as I added a Pertronics ignition in August.  All fuses (all glass) pass smell, sight and continuity tests.  Looking at my wiring schematics, I have deduced:

  1.  The inoperable lighting is all driven off fuses 1, 2, and/or 3.  But, these fused are all "OK".
  2.  Many, but not all (front marker lights, under-hood light, instrument lights) lights share a common ground in the rear trunk wall.
  3.  ALL, as in ALL, of the inoperable lights are controlled by the main light switch (first detent), and none of the working lights are!!

  So, methinks that I have a faulty light switch.  The switch is original (125K on the car).  Can't say I have operated this switch but maybe two dozen times since purchasing the coupe in 1999. What do you people think about this situation?

  TIA,

  Gary Burke
  1973 3.0 CS
  +2240356+






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