79 R65 Wiring Question

[Crossrodes]

There are 3 relays attached to the frame, under the gas tank, on my bike.  

The forewardmost  relay is the ignition relay.  There is a black wire attached to the pin (#87) on the relay.  I can't figure out where this wire is supposed to lead to.  Right now it is detached and everything seems to be fine (the bike runs).  But I'm sure it has some function.  Can anyone with and 79 tell me where this runs to?  Looking from the right side of the bike with the gas tank removed it is the furthest wire in on the relay.  It is about 6 or 8 inches ling and has a black slip on connector.

[Mike V]

Crossroads,
Hopefully this information doesn't confuse things for your '79, I'm attaching a link of the wiring for my '81. There should be 3 relays, from front to back (on my '81) turn signal relay, starter relay, and headlight relay. The black #87 pin should be a jumper from the light relay to the starter relay and grounded at the starter motor. Hopefully our bikes are similar, maybe someone with more model/year knowledge can confirm. If the link does not come through clear enough let me know and I can forward the original pdf.

http://i428.photobucket.com/albums/qq8/gruntyman66/81%20R650%20Restoration/Electrics/81R65LightingDiagram.jpg

Mike V. / San Diego

[Barry]

Mike

I have a 79 wiring diagram which shows a black wire marked "US only" on terminal 87 of the starter relay. It is connected to Terminal 85 on the Light relay which is also marked "US only".  

The diagram is attached but it's not very good quality.

[Mike V]

Barry,
I'm glad you brought that up - I'm currently restoring my electrics and I've found an inconsistancy (I didn't say error) in the available diagrams and the actual backing plate stampings on my light relay. I've double checked the stamping and I've found the green wire (#15) from the ignition switch is connected to the #85 pin of the light relay (not #86 as shown on the digram). And, the black jumper ground wire from the light relay #86 on my relay stamping (not #86 as shown on the diagram). That black wire then jumps to the #87 pin on the starter relay. I've made this revision on my personal Lighting Diagram Chart shown with a hyperlink in the previous post. It would be interesting for another 81 R65 owner to remove the light relay and verify the backing plate numbering with the positions of the factory colored wires into the female connector. Maybe we've discovered something here or I have a mutant relay.

Mike V. / San Diego

[Mike V]

Sorry guys, make that the #56 pin (green wire) from the ignition switch, not the #15, to the light relay.

Mike V. / San Diego

[Crossrodes]

Guys thanks for your help.

I'm going to take a good look at this diagram and how it compares to my bike Barry.  I suspect that the wire in question does not lead to another relay because of the connector on it.  Also I checked the position on the light relay and it is occupied. The connector on the end of this wire is a BMW black plastic covered female spade connector...the same type as are on my coils.  I believe that the connectors that lead to the other relays are bullet type connectors...I could be wrong about this and I will check.

The wiring on this bike has been changed by a previous owner.  The bike was originally built for the German market and was imported to Canada when the owner moved here.  It had an ignition lock in the side of the headlamp.  The ignition lock has been moved to the rubber console above the handlebars.  I suspect the rubber console was also added at some time in the past.  So I'm guessing there have been some wiring changes also.

This wire may have been left loose because of the changes.  I'll let you know what I find.

[Barry]

Mike and Mike V

My posted diagram is so poor it's hard to tell.  

I do have another diagram for a US 78 R65 which shows the relays schematically with no termination numbers. This shows the black wire from an open contact (#87) on the starter relay connected to what I think is the +ve coil connection on the Lighting relay.  According to the Din Standard that would make it #86 as #85 would be the -ve side of the relay coil.

All this is theory as I don't even have the Lighting Relay on my bike.

This diagram is I think too large to post at 1MB even though the quality is not that good.  I can e-mail a copy if anyone wants it.

DIN standard termination numbers which I think came from a previous post here.

Relay
85 relay coil -
86 relay coil +
Relay contacts
87 common contact
87a normally closed contact
87b normally open contact
88 common contact 2
88a normally closed contact 2
88b normally open contact 2

[Justin B.]

I think what this "USA Only" wire's purpose is for is to kill the lights when the starter is being cranked.  The guys on the other side of the pond don't need this as they are trusted to know when to use their headlight so their bikes are equipped with a light switch and they are able to turn the lights off when cranking!

[Mike V]

Justin,
You're right (again). The wire is a bypass to transfer all power to the starter.

Mike V. / San Diego

[Crossrodes]

Well that makes sense Justin.  The ignition switch on this bike has a position where you can start the bike without the lights on.  I guess I can just leave this wire disconnected.

[Justin B.]

If you can start the bike in the "parking light" position then somebody has re-wired the ignition switch (common).  The only down-side is that you can insert a blank key into the ignition (at least on all of ours) and turn it to the "park" position.  You know what kind of issues that could cause...