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wiring diagram missing info?

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i've been fixing previous owner hacks on my 1970...

in order to understand what the heck is going on under the dash, i started tracing over this wiring diagram i found at http://www.2002tii.org/diagrams/bmw2002-usa-early.pdf 

and creating a true-to-color wiring diagram. i'm learning tons by doing this and making sense of the mysteries of wiring. 

 

i noticed 2 things though:

1) there is a strange gap in the diagram to the right of #18, the wiper delay relay (circled in red)

there's a green/blue wire going up that disappears and a green wire coming down that disappears. 

does anyone know what's going on here?

 

2) what are the 2 things (also circled in red) that are underneath the battery and above the brake switch #11

 

screenshots of before and after tracing wires:

 

Screen Shot 2019-09-18 at 7.52.23 PM.png

Screen Shot 2019-09-18 at 7.52.47 PM.png

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my diagram (TI typical) shows that

1) these two ends connects so it is blue-green all the way to that junction (X). There is that cab in "North America typical" diagram).

 

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hi geoff 👋 it's phil, i almost bought your nevada 1970 - maybe i should have after going through this wiring! ha. 

 

for #1, i know it's the wiper delay, but what's going on directly to the right,  where the green wire & blue/green wires just stop and disappear into the ether?

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I have a 1970 automatic and there is no wiper delay, it is just a two speed switch. There is a washer function which activates the pump and presumably the wipers but with mine you have to activate the wipers and then pull on the right hand single light stalk to activate the pump.

Sent from my STH100-1 using Tapatalk

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As Tzei said.

 

You diagram is missing the horizontal line that joins the two "going nowhere" lines.

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(edited)

Hey Phil!

Hopefully your wiring is not all that bad...right?!

 

that 'freelance' wiring is alway a huge mess to deal with ... but honestly ... it all fits on one (reasonably sized) page ... 

not sure what you ended up with ... but there are a few decent color PDFs floating around ... 

i have one that is reasonably correct for a 1602 ... LMK and I can send it along ...

 

 

I'm sure you'll sort it out ... 

 

its gotta be better than whatever the PO(s) did to my Syncro!!

 

 

geoff

 

 

image.thumb.png.834958062ec98ffb49f010e6554df7a0.png

Edited by Geoff Raynak

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FYI, BMW didn't start fitting wiper delay relays from the factory 'till the '75 models.  They made a kit available for the 72/73 cars that turn the wipers on/off by pushing in the turn signal switch (stalk), but they weren't fitted at the factory.  So your '70 doesn't even have a provision for a wiper delay--and no relay, so you have to fit an aftermarket relay. 

 

Squarelights not equipped with the delay feature could be retrofitted with a kit from BMW (7 terminal wiper relay and a three position wiper stalk) as they were all pre-wired from the factory.  The 72-73 kit included a wiring harness as those cars weren't pre-wired, so you got a 7 terminal relay, three position dash switch (for wiper speed) and a wiring harness.  

 

mike

PS--easy source of 7 terminal relays:  E21's were all so equipped.

 

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Nice history Mike ...
Sorry if I was not 100% accurate with my note ...

that missing 'relay' is not an intermittent wiper relay ... it is a 'windshield washer delaying relay' ... 

OEM #61318650178 ... NLA (of course)

and i'm sure you know ... but for others:

 

this relay was designed to have the wipers stay on for a period of time after the wiper washer pump was energized

it is a fascinating little canister ... mine is 100% shot (as per testing below)... so of course i took it apart.

 

here is how i believe it to work:

  • turn signal stalk (item #25) has a reed switch that completes the ground loop for the wiper fluid pump
  • the current flows from pin 15 through the pump (#16) to pin 31b
  • [ed: i know the electrons actually flow the OTHER way ... but let's just leave that for another conversation]
  • the current ALSO flows through the delay relay (#18)
  • this has a bimetallic switch that heats up the wire and bends it
  • this wire activates the 'W' pin (W on diagram ... M in shop manual!) on #18 that in turns activated the wiper motor (17)
  • when you release the turn signal stalk ... current stops flowing ... and in a certain amount of time ... the bimetallic cools down ... and retracts from 'W'/'M' ... and breaks the current loop to the wiper ... 

it is an amazing little electro-thermal-mechanical delay relay

today we just use IC chips ... how boring

 


 

 

 

image.thumb.png.60c2bb99508a5327a8df8e812b1c4cb1.png

image.thumb.png.2af32d4422eb7a92c0fefc4438097e91.png

 

 

image.thumb.png.cf20ade95faf6e04154f7e149d74adc3.png

 

image.thumb.png.80682b857c8a3926f8078bc94577f645.png

image.thumb.png.85cd4ee43c525c448e7135f450eed021.png

 

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Geoff, the relay you refer to (used on the pre-modell 71 cars) is a bi-metal strip timing relay, similar in operation to an old-style electro-mechanical turn signal relay.  While they're NLA, often they can be made to work again by carefully prying back the aluminum cover to expose the innards.  Then take a close look at the points inside, and clean 'em if necessary.  Then test by plugging back in with the cover still off.  If they now work, you're good.  If not, try bending the points a little closer together to see if that works--the electromagnet that pulls the points closed may have weakened over time.  If that doesn't work...you'll have to find another one.

 

mike

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And with regard to that NLA washer-delay relay, I think I've figured out a replacement solution using a boring-but-cheap IC relay from eBay. I'll post info on it whenever I get around to putting it together... and verifying it works!

-Dave

Posted from my phone.

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