Mystery Wire

[stevenrankin]

So, I am changing my left switch gear on my 84 R80RT from the US headlight on all the time version to a version with the added headlight off, parking light, headlight on switch. This switch also came from an 84 R80RT, simple yes, well yes and no. I have a mystery wire in the "new" switch. One that is not on any of the wiring diagrams I have at hand or have found on line. My eyes tell me it is either Green/orange or Green/brown and it is part of the switch assembly, not an add on.

I am assuming the switch I am installing is the UK/Euro version of the switch gear and I would think BMW would have a wiring diagram showing the UK/Euro version, alas, no, I have not been able to find such a thing.

The ONLY time I see this color wire is in a wiring diagram for /6, R90S bikes. The wire goes from the switch to the headlight relay which makes kind of sense to me.

Anyway, here are pictures of the two switches, and the mystery wire, any ideas as to where it should go would be helpful. St.

 

[jagarra]

My first inclination is that it is a parking light wire which was common for European models. Have you found a switch location to select this wire or is that part of the mystery.

 

[stevenrankin]

Mystery

This color wire does not exist in any wiring diagram for this year bike.
I suppose I could fiddle with the switch and a circuit tester to see which one of the switches it is hooked to.

On the wiring diagram for the /6, R90S bikes, this color wire runs from the switch gear to the headlight relay. Without further testing this makes sense to me.

The greatest mystery is why in the heck BMW doesn't have a wiring diagram showing this switch combination, or if they did, why can't I find one? I mean, as this is most likely the UK/Euro version, I would think there would be an existing wiring diagram. Now if this is a police bike add on, it would be possible there is not a diagram.

I have a fairly good idea as to the purpose of this wire and where it goes, I would like to have a bit more understanding before I power up the system. St.

 

[PAS]

Why not join this group and ask.
https://www.bmbikes.org.uk/index.php?sid=6656166580c7549f69d67fcf98362060

 

[stevenrankin]

UK club

Thanks for the link, I will check them out and who knows, may join. St.

 

[pauls1150]

Green with a brown runner (or brown w/ a green runner?) may infer that it is a common "Return" or a -V hookup.
Hey, with those controls all upside down, the electrons are gonna fall out...

 

[20774]

More wiring diagrams here...page is in German! But I don't think I see the colors you're looking for.

https://www.powerboxer.de/schalt-wartungsplaene/110-schaltpl-foxer

 

[stevenrankin]

So far

So, the fellow who I purchased the switch off of took pictures of the inside of the headlight shell and the headlight relay before he pulled the switch. I am not sure if I am seeing correctly the mystery wire is just loose and not connected to anything in the headlight? I see it does not appear to be connected to the headlight relay as I was thinking and my information from the /6, R90S wiring diagram would suggest.

So here is the picture of the system in it's original set up, anyone else think the green/brown wire is loose? Does anyone see a connection point I am missing? St.

 

[kinterridge]

View attachment r80 wire d.pdf

Here's a diagram in German location 12 shows a green yellow wire.

 

[stevenrankin]

An older forum thread

I am afraid I don't see the wire in question on the German diagram, this has been kind of the case so far.

So, I had a link provided to me taking me to an older BMWMOA forum post that covers this issue as well as gives the solution. It is a bit hazy, perhaps one of the fellows who wrote in this post if you see this post will follow up and clarify a bit the position of the green orange wire? St.
https://forums.bmwmoa.org/showthread.php?26888-Euro-Light-Switch-Wiring

 

[AntonLargiader]

Steven,

The switch wiring (and changes thereto) is all laid out on my website. http://largiader.com/articles/euroswitch/

You're looking for the table in the middle of the page that compares the wire colors for different generations of the switches.

EDIT: You're actually looking for the "Adding the switch for twinshock models" part.

 

[stevenrankin]

I am missing something

Anton, I did read your article and perhaps I am confused, I don't see the Green/orange wire as shown in my picture with the two arrows pointing to it. Or, is the wire I am seeing as Green/orange really Green/red?

What color do you make it out to be in my pictures? LOL, a faded red could be orange. If the wire in the picture is green/red, it's red looks a lot different from the full red in the red wires, looks like orange.

Sorry, I will have to check the bike in the garage tomorrow morning to see if there is also a green/red wire in the switch bundle. If not, then the only logical explanation is my mystery wire is the green/red wire you mention in your article and its green/orange to my eyes.

I really think this is the answer to the mystery, I am seeing green/orange or as I thought perhaps green/brown but the wire is in fact a strange looking green/red. The red is certainly not as red as the red in the blue/red wire in the switch.

LOL, is it tabasco red, fire engine red, sunset red, LOL. Thanks All of you for answering my post and bearing with me. St.

 

[20774]

Note to self...always check Anton's site for the BMW nuggets!

 

[weschmann]

So, aside from the wire coloring, where did you find the wire to plug into, or was it in fact an optional wire Not plugged in?

 

[stevenrankin]

Final place

So, it is the final plan to plug the mystery wire into the terminal 86 on the headlight relay. This decision has been made with the vast amount of help I got here in the forum as well as from private email correspondence.

LOL, I have to say I was very confused with a wire coloring. Six wiring diagrams many questions, many answers, The final proof will be when I get the bike back together and powered up. But this was a step in the right direction. St.

 

[FELAW]

So, it is the final plan to plug the mystery wire into the terminal 86 on the headlight relay. This decision has been made with the vast amount of help I got here in the forum as well as from private email correspondence.

LOL, I have to say I was very confused with a wire coloring. Six wiring diagrams many questions, many answers, The final proof will be when I get the bike back together and powered up. But this was a step in the right direction. St.

Can you explain why you would plug it into 86 on the relay? Isn't there already a green/white wire there? That idea must have come from your private correspondence as I don't see anything in the posts which would suggest that as an option. (but it is an interesting puzzle)

 

[AntonLargiader]

The green/white is the always-on power that the relay originally had. This gets replaced with the switched power from the new euroswitch.

 

[AntonLargiader]

Steve,

I found a good diagram of the Euroswitch wiring. It's on my website page now. Still researching the different relay that is shown. From what I can see, models without the switch had a diode in the relay. A guy on ADV reports that when he puts both the key and the switch into Park, he has full power backfeeding to the bike. Not sure if that is the relay or just a miswiring on his part. I have a note on my page that says that the headlight may come on with cranking if you have the wrong relay. I haven't spent time yet figuring out the full consequences of having the wrong relay.

 

[stevenrankin]

Relay

Hello Anton, IkChris mentioned changing relays in an older MOA post, I added the link to the post here earlier. I sent him a private message asking for clarification have yet to hear from him.

Meanwhile, I will check out your site and look to see if I can get the Euro relay or at least find a source just in case.

Thanks for the help. St.

 

[AntonLargiader]

Yep, I remember that and I posted in the ADV thread how the relay does provide that separation between the two park circuits. At first glance I don't see why the diode would affect it, but a) i have a stuffy head and am not at my best, and b) the euro diagram has 85 and 86 reversed at the relay. Which wouldn't matter if you are using the non-diode relay, but it just throws a wrench into the troubleshooting if one has a stuffy head.

85 and 86 are the relay coils. DIN convention is to ground 85. The BMW switched headlight diagram (without diode) shows 86 being grounded. The US headlight diagram shows 85 grounded. The diode connects to 86, theoretically allowing current to flow from ground to 87b (like that is going to happen) if one were to have the diode relay and the euro harness as literally described.

On your bike, which (85 or 86) is the brown wire at the relay? 85 I assume. I have no idea if they actually wired the euro bikes differently or it's just sloppiness on BMW's part.