Ignition switch

73E9er

Member
Messages
32
Reaction score
0
Location
Lake Oswego, OR
Took the coupe (1973 3.0 CS) out for a spin a week, or so, ago - on one of the best days of the year (weather-wise) so far this year here in Oregon. Just HAD to get out of the house and get some seat time. Returned home with a BIG smile on my face, pulled into the garage, parked the coupe, and shut it off. Was half way out the door when I sensed something was wrong. The car was still running! Not herky-jerking like it might be when experiencing after-shutoff carbon buildup firing, but idling right along at 1000 RPM, smooth as silk.

I looked in my hand to make sure I was not mistaking my previous actions, and sure enough, there were my keys. No indicator (accessory) lights were on on the dash. I inserted the key, turned it clock-wise all the way (no effect), then counter-clock-wise to the "neutral) (running) position - this should have shut off the car, per normal. But noooo... I next turned the key counter-clock-wise again (no effect), and then back to neutral(center), at which time the accessory lights came on. I then pulled the key out, fearful that if I turned it clock-wise again I might engage the starter circuit and really mess things up. I opened the hood and pulled the hot lead from the coil top and, of course, the car stopped running. Mission accomplished. Hmmmm.... Left the car to sit. Dinner was awaiting.

The next morning, I replaced the coil lead, got in and inserted my key and turned it to the accessory position - lights all lit up. Then I turned it to "start" and it fired up just fine, the key returning to the "running" position. I tried shutting it down and experienced all the symptoms from the previous day. Pulled the coil lead to stop the car again. Took the steering wheel off and separated the clam shell halves of the steering post cover. "Nothing to see here, folks." No obvious detached wires, etc. Saw sufficient complexity in the dismounting of the ignition switch itself that I knew doing so was not readily a project for me.

So, at present, I can actually drive the car, but need to shut it down by brute force. Questions for the group: Does this seem to be a de facto ignition switch problem? If so, suggestions on where to locate a replacement? Assuming one can be found, will I have to re-key my car (or at least carry a separate key for just the ignition) or is the pin/tumbler part of the switch able to be transplanted to another switch housing?

Any help here will be appreciated. Thanks.
 

Dick Steinkamp

Well-Known Member
Site Donor $
Messages
2,446
Reaction score
2,865
Location
Bellingham, WA
With mine, the little pawl broke that connects the electrical switching part to the key/tumbler part. It then would work sometimes and sometimes it wouldn't. In my case, the key would engage the starter sometimes and sometimes it wouldn't. Maybe the same fix as yours would be? I don't know these cars well enough to know if your symptoms do or don't indicate the same fix.

The electrical switching part is replaced without touching the key/tumbler part. There is a tiny grub screw that holds the electrical switching part into the key tumbler part accessible once the lower clam shell half is removed.

Just a word of caution....I don't recommend using the common plastic electrical switch replacement that is available from just about everywhere including eBay for $60-70. It must be highly modified to fit and work. WN and others sell the OE metal one for lots of money, but it is worth it (if that turns out to be your problem).
 

Koopman

Well-Known Member
Site Donor $
Messages
2,675
Reaction score
614
Location
Uxbridge,Ma
Hi Dick. I still have the switch if you want I can send it to you to try and see if that's the problem.
Harry
 

73E9er

Member
Messages
32
Reaction score
0
Location
Lake Oswego, OR
My independent BMW service outfit has located a BMW switch that is to arrive this week. Will post the results of that installation soon (I hope!).
 

eriknetherlands

Moderator
Site Donor
Messages
2,748
Reaction score
1,993
Location
Netherlands, Eindhoven area
it is this screw, looks like an M2 screw. originally covered with a dab of red paint (it was in my car at least like that)
 

Attachments

  • 20200606_205020.jpg
    20200606_205020.jpg
    265 KB · Views: 121

73E9er

Member
Messages
32
Reaction score
0
Location
Lake Oswego, OR
Sooner - Thanks for the offer. I'll soon find out if I need it or not. My problem can only be in the electrical pig tailed switch, or the barrel, key "switch" ( like yours). I am hoping (as does my mechanic) that the pig tailed electrical switch is the culprit. One, or more, of those 48-year old solder joints most likely gave out. I had to "repair" my wiper stalk on/off switch for that very reason.

I'll post results soon - my replacement switch is expected in town Friday or Monday next.

Gary
 

73E9er

Member
Messages
32
Reaction score
0
Location
Lake Oswego, OR
Well... it seems I was wrong about "my problem can only be...", above. It was neither the electrical pig-rail plactic/metal capped switch part NOR the key/pin tumbler switch mechanism. It was the barrel housing that houses those two switches. See pics (sorry, I do not have a digital camera that provides close-up resolution). This part has a nylon cam and an internal spring that returns the key tumbler switch to the "run" position after one releases the key after starting the car. My spring and/or cam either broke or died of old age.

My shop located what must be the LAST such part in BMW's inventories - in Munich and at dealers worldwide. Coupe now starts and runs just like it did before and I am a happy camper.

Thanks for all the offers and advice. Can't beat this forum for support and friendship. Freud am fahren.
 

Attachments

  • DSCN0473.JPG
    DSCN0473.JPG
    143.2 KB · Views: 94
  • DSCN0475.JPG
    DSCN0475.JPG
    104.5 KB · Views: 89
Top