- Remove Turn Signals, Parking Light, Head Light, Instruments, Ignition
- Remove Electrical Components
- Remove Rear Wiring Sub-harness
- Remove Rear Tail Light and Turn Signals
- Remove Rear Brake Light Switch
- Remove Clutch Switch & Neutral Switch Sub-harness’
- Remove Main Wire Harness
- Various Wire Harness’
Remove Turn Signals, Parking Light, Head Light, Instruments, Ignition
I show how I remove the body panels, front turn signals, parking light, head light, dash, instruments and ignition switch, rear fender, rear tail light and turn signals in this write-up.
- 46 BMW 1977 R100RS Remove, Disassemble Body Work
There were changes made in the wiring to install heated grips and VDO oil pressure and temperature gauges. However, none of these were working: the wiring to the gauges had been cut and the heated grip wiring had been patched and disconnected.
Remove Electrical Components
The bike was updated with dual plug heads and a Dyna III electronic ignition. The stater relay, horn relay and voltage regulator are stock. Removal is straight forward. I took pictures and labeled wire ends to simplify installation.
Remove Voltage Regulator
This is the large rectangular can on the right side of the bike under the gas tank. There is a triangular plug that goes into a socket in the bottom. The wires come from the alternator inside the front cover. I remove the triangular plug and unscrew the Allan head bolts to remove the voltage regulator from its bracket.
Remove Dyan III Coils and Ignition Module
The bike has dual plug heads and uses the Dyna III two port coils (red). The green/blue wire from the main harness plugs into the outer lug of the left coil. The red wire from the Dyna III ignition module plugs into the other spade of the same lug. A second lug toward the inside of the bike has a black jumper wire that plugs into the inside lug of the right coil. These are 6 volt coils, so the black wire puts them in series for the 12 volt ignition system.
The right side coil has a brown wire from the ignition module that plugs in a spade on the outside lug. Note the black ground wire from the ignition module is connected to the right side top engine cover allan head bolt per Dyna instructions.
The ignition module has six wires: a bundle of red, brown and black that go to the coils and ground to the engine and two other wires, red and white, that connect to the hall effect sensor (aka, points) inside the front cover. I remove the module and unplug the two red and white wires from the leads going to the hall effect sensor.
Remove Starter and Horn Relay Sockets and Remove Wires
These are located under the gas tank on the left side opposite the voltage relay.
In front of the relay sockets is a white plastic connector with blue wires. I unplug these.
I unplug the relays from the sockets There is a lot of corrosion on the relay prongs and inside the sockets where the female terminals are located. I plan to replace the relays. I remove the female terminals from the sockets so I can clean them up.
The sockets have a keyed side so they can connect to each other. I slide them apart so I can remove the wires going into the bottom of the sockets easier.
I use a small, thin, flat blade screw driver to compress the tab on the side of the female terminals inside the socket so I can remove them. As shown here, the slot is the small rectangular hole centered next to the longer slot the female terminal fits into.
I find pushing the screw driver into the slot and twisting it a bit while pulling on the wire makes it pretty easy to remove the terminals from the socket.
As I remove the wires from the sockets, I make a diagram showing the location and color of each wire so it will be easier to connect them again. This is my short-hand for the colors:
Some of the wires I labeled as “Brown” (BR) are actually red. The insulation had discolored. I figured this out when I put the cleaned wires back into the sockets. See the write-up about installing the wiring and electrical components where I have a video showing how to use the wiring diagram and the terminal numbers on the sockets to ensure the correct wire goes into the correct hole in the socket.
The starter relay has wires from the main wiring harness, the (+) battery cable and from the alternator inside the front engine cover via the front slot of the inner cover. The horn relay has a jumper from the starter relay socket, a ground wire, a black wire going to the horns and a wire coming from the main harness that goes to the horn button.
Remove Rear Wiring Sub-harness
The wiring to the brake light and turn signals goes through a separate sub-harness that plugs into the main harness near the left side of the battery box.
The sub-harness routes inside the rear sub-frame via a hole near the left handhold and a second hole at the back of the sub-frame in the middle.
Remove Rear Tail Light and Turn Signals
This shows how I removed the rear tail light assembly and the turn signals from the rear wire harness.
- 46 BMW 1977 R100RS Remove, Disassemble Body Work
With the wires disconnected from the tail light and turn signals, the rear sub-harness can be pulled through the sub-frame to remove it. Since I am going to clean the terminals on the rear sub-harness, I remove the male pins from the rear sub-harness and pull it out the rear hole using the round male terminal pin removal tool. I make a sketch of the pin locations in the plug before removing them.
Here is the rear sub-harness with tail light attached with the rear sub-frame removed.
Remove Rear Brake Light Switch
There are two wires that go to the rear brake light switch. I remove the rubber cover, then the two screws securing the switch and remove the two wires.
Remove Clutch Switch & Neutral Switch Sub-harness’
The clutch lever has switch and a small sub-harness that attaches to a plug in the main harness near the left side of the steering head. There is also a short sub-harness that connects to the neutral and oil pressure switches. This plugs into the main harness near the left front foot peg. I unplug these sub-harness’.
Remove Main Wire Harness
With all the electrical components and sub-harness’ disconnected from it, I remove the main wire harness. I snip the zip ties securing it to the frame with wire cutters. As I pull it forward, I label the branches and ends of wires with the component they connect to so it will be simple to reinstall it. When the main harness hangs down beneath the headlight bucket, I remove the headlight bucket with the main wiring harness and handle bar switch wire harness’ attached.
Various Wire Harness’
Here is a summary of the various wire harness’ I removed.
Main Wire Harness
Here is a photo of the main harness showing what the branches connect to.
Fairing and Instrument Panel Sub-harness
Here is the fairing and instrument panel sub-harness. The ignition switch wires are part of the main harness.
Heated Grips Sub-harness
This is the heated grips on-off switch and sub-harness.
And the rear sub-harness with the tail light and turn signals still attached to it is shown below. Note that I removed the plug that goes on the end of this harness so I can clean the pins.