Wiring question.... you can run away now!

[visian]

Greetings.

I am refurbishing my 1986 R80G/SPD and part of the work is a new wiring harness. Things are going pretty good but I've run into an issue trying to reverse engineer several things that have happened in the past.

The history of the repairs are 1) addition of accessories when new... Bosch Driving Lights, Tachometer and Voltmeter Instrument Pods. 2) Dyna Dual-plug Ignition, 3) Motorrad Elektrik Voltage Regulator and Omega Charging System And 4) Fixing a meltdown that happened after doing something stupid with the two small fuses in the box at the rear of the backbone tube (I am not sure, but this fuse box may be unique to G/S).

In the Existing Wiring image above, Relays 6 & 7 were interconnected with each other in sort of a puzzling way, which is not visible in the photos..

There is a Red power wire coming from the battery into Relay 7, and from the same connector another Red wire goes to Relay 6. This makes me think that Relay 7 is the Starter Relay, based on the wiring diagram that I have. (see bottom of post).

From Relay 6 there is a Brown/Yellow Stripe wire goes into a taped-off ball, together with a Yellow wire (the two are not connected inside of the tape ball, but they are male/female so they could be connected) that goes into a splice on the Yellow wire going into Connector 1. It appears this yellow wire spliced into Connector 1 is doing nothing... but it could if the two wires in the ball were connected.

From Relay 7 there is a White wire going into a splice on the White wire going into connector 1. The photo of these splices is below. This is probably doing something related to the lights and the ignition switch. (deduced from the Wiring Diagram). I suck at reading wire diagrams.

There is one Brown wire coming from Relay 6 and another coming from Relay 7 that go into another taped-off ball. Out of the ball comes one brown wire that then connects/grounds to one of the bolts holding the Voltage Regulator. It was clear that this wire is not stock because the eye connector was not stock.

This second ball is probably where the meltdown happened. There are also a White/Black wire coming from Relay 7 going into this ball, and a Yellow/Black wire coming from Relay 6. All these wires are pretty heavily melted together and I the tech basically wrapped off everything, spliced in a Brown wire and grounded them to the Voltage Regulator mount.

It appears that all these two relays are doing is powering something and grounding something.... is it the headlight via the splices at Connector 1?

I don't think these white and yellow splices at Connector 1 are needed any more, right?

Maybe I do not need to replicate this whole mess? There is nothing in the new harness that any of this would connect to.

Advice is greatly appreciated.

Ian

 

[visian]

Are Part #s 61 12 1 244 175 & 1 12 1 244 272 (#11 & 12 in diagram) possibly the thing that melted down? Of course, that appears to be NLA....

 

[20774]

Ian -

This is all very confusing. For example, you mention a white wire from #7 but the wiring diagram doesn't list such a colored wire. I would think you'll need to follow each wire and document what connector they go to in order to figure things out. You show "Starter Relay?"...again, identifying the wire colors and connectors would help to confirm if it is the starter relay or not.

I guess the G/S is different than earlier bikes...I thought most of the relays were on the left side of the backbone.

 

[AntonLargiader]

The G/S bikes I have in the shop have an earlier backbone. Yours is like the early R100GS. Mine only have the starter relay, flasher unit and headlight relay.

Based on the appearance and the result of the wiring you had, I would install 100% stock and just have the three relays I mentioned. Then use those rear relay positions to fabricate the driving light harness from scratch. You can install a left control switch with a headlight switch, reconfigured to use the headlight switch to control the driving lights. I've done that on a few G/Ses now.

The add-on instruments have no connection to those relays.

 

[visian]

The G/S bikes I have in the shop have an earlier backbone. Yours is like the early R100GS. Mine only have the starter relay, flasher unit and headlight relay.

Based on the appearance and the result of the wiring you had, I would install 100% stock and just have the three relays I mentioned. Then use those rear relay positions to fabricate the driving light harness from scratch. You can install a left control switch with a headlight switch, reconfigured to use the headlight switch to control the driving lights. I've done that on a few G/Ses now.

The add-on instruments have no connection to those relays.

Thanks, Anton.... after a lot of head scratching I am pretty sure the whole second set of relays was affiliated with the Bosch driving lights that were on the bike. They had a unique setup, with a handlebar switch to turn the power on, where one or the other would be lit depending on the low beam/high beam status of the headlight. That is, both were never on at the same time, probably to conserve the power coming from the weak generator.

This arrangement actually became handy after busting one of the Bosch lights off the bike. I replaced them with Saeng Nightcutters... one for fog (low beam) and the other a spot (for high beam). All this ultimately got replaced by a set of PIAA LEDs with their own wiring harness.

My guess is that this whole mess wound up doing nothing, so I'll go with the stock setup and see if it starts up.

Thanks!

Ian

 

[visian]

Ian -

This is all very confusing. For example, you mention a white wire from #7 but the wiring diagram doesn't list such a colored wire. I would think you'll need to follow each wire and document what connector they go to in order to figure things out. You show "Starter Relay?"...again, identifying the wire colors and connectors would help to confirm if it is the starter relay or not.

I guess the G/S is different than earlier bikes...I thought most of the relays were on the left side of the backbone.

Kurt - See my reply to Anton.... I think these wires were not documented on the wiring diagram because they were for some accessory lighting.

There are yellow and white wires coming from the headlight and "dip switch" (high/low beam) and those were probably used in conjunction with the two undocumented relays to power the accessory driving lights.

Last, I think my bike is right on the border line between the old G/S (1986) and the new GS (1987) and very well could have had an updated frame.

Ian

 

[AntonLargiader]

That makes sense. The K75 had the same kind of fog/driving light setup as an option, and it explains the two relays. I'm not familiar with it personally but I know Paul Glaves has written about it.

All Monolevers have the relays on the right, with the asymmetric tunnel under the tank. Relays on the left is an old twinshock thing. I've worked on an '87 G/S but I don't recall if it had the extended relay mounting plate like yours. Until yesterday, I didn't know that existed on any G/S.