I'm sure most of you recognize this little rat nest...where the crankshaft speed sensor and the cylinder identification sensor meet the wiring harness. Our engineering friends at BMW cleverly decided to use the SAME connector for both sensors, and thought that if they just made one set of bracket cutouts upside down, you couldn't mix them up. Well, that usually works if you are just replacing one sensor at a time. The problem is I am in the middle of a full rebuild with both sensors off the engine. I realized the sensor lead lengths were long enough that they were interchangeable...bad news. OK, the next step was to pull back the rubber boots on the harness plugs and check the wire colors, then go to my official electrical manual to see which was which. The first plug had black, yellow, and grey...so far so good. The second plug...had black, yellow and grey....I could hear legions of BMW engineers laughing at me! The next step was to trace where the wires went, so it was back to my trusty electrical manual. Lessee...the black wire from the cylinder identification plug goes to pin 8 of the Motronic (or is that Moronic) unit, the black wire from the crank speed plug goes to pin 47. Next step is to pull out my Fluke meter and set it on diode mode...first plug black and check at pin 8...BEEP...success! I added some dots of color to each connector so this can't confound me in the future...that is, if I remember to write my color codes down somewhere safe (so safe I will forget where I wrote them by the next time I do this...it's fun getting old!)
Announcement
Collapse
No announcement yet.
You've got to think like a German engineer...
Collapse
X
-
You've got to think like a German engineer...
I'm sure most of you recognize this little rat nest...where the crankshaft speed sensor and the cylinder identification sensor meet the wiring harness. Our engineering friends at BMW cleverly decided to use the SAME connector for both sensors, and thought that if they just made one set of bracket cutouts upside down, you couldn't mix them up. Well, that usually works if you are just replacing one sensor at a time. The problem is I am in the middle of a full rebuild with both sensors off the engine. I realized the sensor lead lengths were long enough that they were interchangeable...bad news. OK, the next step was to pull back the rubber boots on the harness plugs and check the wire colors, then go to my official electrical manual to see which was which. The first plug had black, yellow, and grey...so far so good. The second plug...had black, yellow and grey....I could hear legions of BMW engineers laughing at me! The next step was to trace where the wires went, so it was back to my trusty electrical manual. Lessee...the black wire from the cylinder identification plug goes to pin 8 of the Motronic (or is that Moronic) unit, the black wire from the crank speed plug goes to pin 47. Next step is to pull out my Fluke meter and set it on diode mode...first plug black and check at pin 8...BEEP...success! I added some dots of color to each connector so this can't confound me in the future...that is, if I remember to write my color codes down somewhere safe (so safe I will forget where I wrote them by the next time I do this...it's fun getting old!)Tags: None
-
This is atypical of BMW, and surprised me the first time I ran across it, too-
there are half a thousand connectors on the E36, and none of them that can reasonably
reach each other will plug into each other.
Hell, the radiator hoses on an E46 are keyed- they only go on one way.
The E30M20 was a whopping great stopgap car- lots of old mixed with some new,
and every so often, a WTF like this one. Kind of like the Jag E-type, I think
it surprised BMW a little how many they sold to US yuppie lawyers...
tnow, sometimes I just mess with people. It's more entertaining that way. george graves
-
TobyB...funny you mention the E-type...I never owned one, but did have a 1973 XJ-6. Working on that car was like peeling an onion. .whatever you needed to fix was obscured by several layers of other systems that needed to be removed before you could get to the offending part. And that 4.2L 6-cylinder engine...it was masterful at turning gasoline into heat, cooking everything in the engine bay. A year after my car was built, they had to put a box around the battery with a fan so the battery water wouldn't boil away! BMWs are a joy to work on in comparison.
Comment
-
Yeah, and terrifyingly, that was Jag's idea of cashing in on the success of the E-type by
making a 'production' car.
I helped a friend get an E running once, and it's a lot like working on a kit car-
you can tell they were each made by hand, one at a time, by a guy in a shed.
He got his parts from somewhere else, but then he made them fit.
The story went, they never planned on producing more than a few thousand.
But just like the late '80's with the E30, kids had money in the late '60's, and bought them hand
over fist.
The E30's a little like that, in the BMW sense- I think they just wanted to get on
to the E36, which IS a very productionized car, much to its detriment...
...which just goes to show that you never know what the punters will like, because the 2002's a productionized
NK1600...
tnow, sometimes I just mess with people. It's more entertaining that way. george graves
Comment
-
If memory serves me (and there's no guarantees) it was the Spitfire that had to have the motor mounts released so you could raise the engine....to change the spark plugs.
I love my e30s :)Seat Shocks....I have passed the baton to John Christy from Ninestitch. Email John or Garrett at ninestitch1@gmail.com
https://www.r3vlimited.com/board/sho...86#post4944786
Alice the Time Capsule
http://www.r3vlimited.com/board/showthread.php?t=360504
87 Zinno Cabrio barn find 98k and still smells like a barn. Build thread http://www.r3vlimited.com/board/show...20#post3455220
Comment
-
Originally posted by jeffnhiscars View PostIf memory serves me (and there's no guarantees) it was the Spitfire that had to have the motor mounts released so you could raise the engine....to change the spark plugs.
Comment
-
Perhaps it was the Morris MinorSeat Shocks....I have passed the baton to John Christy from Ninestitch. Email John or Garrett at ninestitch1@gmail.com
https://www.r3vlimited.com/board/sho...86#post4944786
Alice the Time Capsule
http://www.r3vlimited.com/board/showthread.php?t=360504
87 Zinno Cabrio barn find 98k and still smells like a barn. Build thread http://www.r3vlimited.com/board/show...20#post3455220
Comment
Comment