61 BMW 1983 R80ST Remove Electrical System

I acquired this bike as a “project bike”, which means it was partially disassembled. The headlight, dash with the instruments and ignition, and the coil weren’t on the bike, so I don’t show how those are removed. But, I will show how they are installed when I get that far.

1983 R80ST As Delivered To Brook's Airhead Garage

1983 R80ST As Delivered To Brook’s Airhead Garage

NOTE:
I indicate wire colors with all BOLD CAPITAL LETTERS for the solid color and Bold Initial Capital for the stripe color, e.g. GREENBlack indicates solid green with a black stripe.

R80ST Wiring Diagram

This is from the Haynes manual. There are errors in many wiring diagrams, but I like the colored wiring shown in the Haynes manual.

Wiring Diagram For R45, R65, R65LS and R80ST, 1981-1985 [SOURCE: Haynes Manual]

Wiring Diagram For R45, R65, R65LS and R80ST, 1981-1985 [SOURCE: Haynes Manual]

Video Summary

The following video provides an overview of the R80ST electrical system.

VIDEO: 1983 BMW R80ST Charity Build: Electrical System Overview

Headlight Shell & Instrument Cluster Wiring

Although the headlight and instrument cluster weren’t on the bike, I will show the wiring that goes to those components.

The headlight shell on the R80ST does not include the wiring board that is common to many airhead models.

Headlight Wiring Terminal Board Mounts Inside Many Airhead Headlight Shells, But Not The R80ST[Source: MAX BMW]

Headlight Wiring Terminal Board Mounts Inside Many Airhead Headlight Shells, But Not The R80ST[Source: MAX BMW]

Typical Headlight Shell With Connector Board Creates A Wiring Maze

Typical Headlight Shell With Connector Board Creates A Wiring Maze

And, the turn signal relay and ignition switch are not inside the headlight shell either. All that’s in the headlight shell is the headlight assembly, with the headlight and the parking light bulbs.

Inside R80ST Headlight Shell-Just Headlight & Parking Bulbs

Inside R80ST Headlight Shell-Just Headlight & Parking Bulbs

Here are the loose wires at the headlight end of the main wiring harness that connect to the headlight, parking light, tachometer with indicator lights, speedometer, ignition switch, turn signal indicators, and the front turn signals.

Headlight End Of Main Wiring Harness

Headlight End Of Main Wiring Harness

Tachometer Wiring

The electronic tachometer contains the indicator lights for neutral, charging (aka GEN), low oil pressure and high beam. Therefore a number of wires go into it via a round plug the connects to the back of the tachometer housing.

Tachometer Has Four Indicators At Bottom: GEN, Oil, Neutral, High Beam

Tachometer Has Four Indicators At Bottom: GEN, Oil, Neutral, High Beam

Tachometer Back Showing Round Male Wiring Socket

Tachometer Back Showing Round Male Wiring Socket

Main Wiring Harness Tachometer Round Female Plug

Main Wiring Harness Tachometer Round Female Plug

Headlight Shell Wiring

The headlight plug was replaced so there are a number of splices that were not well soldered with a lot of electrical tape.

Headlight & Parking Light Sockets-Lots of Electrical Tape

Headlight & Parking Light Sockets-Lots of Electrical Tape On Headlight Socket

Headlight Socket Attempted Repair

Attempted Headlight Socket Repair

Instrument Cluster Wiring

The speedometer and tachometer attach to the top flange of the headlight bracket. Each has a strap around the body with two M5 studs that fit into the slots of the headlight bracket arm (see later picture of headlight bracket). The plastic instrument housing slides over the speedometer and tachometer and the bottom cover is secured with two screws, one on each side of the bottom cover. The instrument housing has a left and right turn signal indicator and the ignition switch installed in it. It also has two slots at the bottom and one in the middle for adding switches for optional accessories.

Instrument Housing

Instrument Housing

Inside Instrument Housing-Turn Signal Flashers (Green) With Ignition Switch Hole Underneath

Inside Instrument Housing-Turn Signal Indicators (Green) With Ignition Switch Hole Underneath

Instrument Housing Fits Over Speedometer and Tachometer That Attach To Headlight Bracket Tab With M5 Bolts On The Side

Instrument Housing Fits Over Speedometer and Tachometer That Attach To Headlight Bracket Tab With M5 Bolts On The Their Sides

The ignition switch plugs into the dash and connects to the main wiring harness.

Ignition Switch Wires

Ignition Switch Wires

The turn signal indicator inside the instrument housing has a left and right arrow. The BLUERed is the left indicator and the BLUE-Black is the right indicator. There is also a GREY-Black wire that powers the speedometer illumination bulb.  I’m missing the left turn indicator and speedometer illumination bulb sockets.

Left Turn Signal Indicator (BLUE-Red), Speedometer Illumination Light (GREY-Black), Ground (BROWN) Wires

Left Turn Signal Indicator (BLUERed) and Speedometer Illumination Light (GREY-Black), Ground (BROWN) Wires Are Missing Their Sockets

Right Turn Signal Indicator (BLUE-Black) & Ground (BROWN) Wires

Right Turn Signal Indicator Socket & Bulb (BLUE-Black) & Ground (BROWN) Wires

Front Turn Signals Wiring

The turn front turn signals fit onto a stalk on the bottom of the headlight bracket. The speedometer and tachometer mount on either side of the middle tabs at the top of the headlight bracket.

New Headlight Bracket With Turn Signal Stalks At Bottom

New Headlight Bracket With Bracket For Tachometer & Speedometer at Top And Turn Signal Stalks At Bottom

Left Front Turn Signal Wires

Left Front Turn Signal Wires

Right Front Turn Signal Wires

Right Front Turn Signal Wires

Remove Electrical Components Under Gas Tank

There are a number of electrical components under the gas tank along the right side of the spine tube. Some of the electrical components are shown in the picture below. The front of the bike is to the right. The components from right to left:

  • Ignition Coil (Not Visible and Missing on This Bike)
  • Plugs For Handlebar Combination Switches (Red, Black and White Plugs)
  • Electronic Ignition Control Unit (Cooling Fins At Front)
  • Voltage Regulator (Rectangular Silver Box)
  • Auxiliary Relays (Small Grey Boxes, Not Stock, But An Option)
  • Starter Relay (Far Left, White Bottom Relay)
  • Headlight Relay (Far Left, Grey Top Relay)
  • Turn Signal Relay (Not Visible, Under Headlight/Starter Relay Bracket)
  • “Special Equipment” Plug (Not Visible, To Right of Headlight/Starter Relays)
  • Fuse Box (Not Visible, Under End of Spine Tube)
(R to L) Electrical Components: Ignition Control Unit; Voltage Regulator; (2) Auxiliary Relays; Headlight and Starter Relays

(R to L) Electrical Components: Ignition Control Unit; Voltage Regulator; (2) Auxiliary Relays; Headlight and Starter Relays

Missing Coil Mounts to Bracket On Right Side Of Spine Tube

Missing Coil Mounts to Bracket On Right Side Of Spine Tube

Turn Signal Relay Socket Mounts on Bottom Of Headlight/Starter Relay Bracket (Relay Is Missing)

Turn Signal Relay Socket Mounts on Bottom Of Headlight/Starter Relay Bracket (Relay Is Missing)

"Special Equipment" Socket At Rear Of Spine Tube

“Special Equipment” Socket At Rear Of Spine Tube Bracket

Fuse Box Mounts Underneath The Rear End Of Spine Tube With Clamp

Fuse Box Mounts Underneath The Rear End Of Spine Tube With A Hose Clamp

On this bike, a previous owner installed two auxiliary relays on the voltage regulator bracket which has holes at the top for an optional twin relay socket. I think these were used to control driving lights as one relay has a YELLOW output wire and the other relay has a WHITE output wire.

Pair Of Identical Auxiliary Relays Mounted In a Dual Socket Plug

Pair Of Identical Auxiliary Relays Mounted In a Dual Socket Plug Attached To The Top Of The Voltage Regulator Bracket

I start removing the components under the gas tank starting from the front of the bike.

Remove Ignition Coil

The coil on my bike is missing. It mounts to the right side of the spine tube with two Allen bolts with wave washers. GREENBlue and BLACK wires connect to the terminals on the coil.

Coil Wires To Missing Coil

Coil Wires, GREENBlue and BLACK, Go To Missing Coil

Remove Handlebar Combination Switch Plugs

The handlebar combination switches sub-harnesses have female plugs that plug into male plugs attached to a bracket welded to the right side of the spine tube under the gas tank. The left handlebar combination switch has two plugs, red and black, that plug into the corresponding color male plug of the main wiring harness, and the right handlebar combination switch has one plug, white.

(3) Main Harness Plugs For Handlebar Multi-function Switches

(3) Main Harness Plugs For Handlebar Combination Switches

Left Handlebar Multi-Function Switch Has Two Plugs

Left Handlebar Combination Switch Has Two Plugs

Right Handlebar Multi-Function Switch Has One Plug

Right Handlebar Combination Switch Has One Plug

(3) Main Harness Plugs For Handlebar Multi-function Switches

(3) Main Harness Plugs For Handlebar Combination Switches

The plugs have tabs on the top and bottom. I depress the top tab with a screw driver while pushing it toward the rear until I get the top tab past the edge of the hole. Then I depress the bottom tab in the same manner to release the plug from the rectangular hole in the bracket.

CAUTION:
The plugs are plastic and if you press too hard on the tab, you can crack the plastic plug. DAMHIK :-).

Plugs Have Tab On Top And Bottom

Plugs Have Tab On Top And Bottom

Pushing Top Tab Down To Remove Plug

Pushing Top Tab Down To Remove Plug

Handlebar Right Side Multi-Switch Cable Plug Removed

Handlebar Right Side Combination Switch Main Wiring Harness Plug Removed From Bracket

Remove Electronic Ignition Control Unit

The ignition control unit mounts on a large shiny heat sink. The heat sink mounts to a bracket on the spine tube with Allen bolts and lock washers. The ignition control unit is Bosch part# is “0 227 100 103”.

Ignition Control Unit Mounts On A Heat Sink That Bolts To A Bracket On The Spine Tube

Ignition Control Unit Mounts On A Heat Sink That Bolts To A Bracket On The Spine Tube

Ignition Control Unit Hardware Detail

Ignition Control Unit Hardware Detail

Ignition Control Unit Bosch Part# "0 227 100 103"

Ignition Control Unit Bosch Part# “0 227 100 103”

The ignition control unit cable plug is secured to the ignition control unit with a wire bail. I use a screwdriver to carefully pry the bail out of the slot it sits in and remove the ignition control unit from the plug.

Ignition Control Unit Plug Is Secured With Wire Bale

Ignition Control Unit Plug Is Secured With Wire Bale

Removing Ignition Control Unit Plug Wire Bail With Small Blade Screwdriver

Removing Ignition Control Unit Plug Wire Bail With Small Blade Screwdriver

Wire Bale That Secures Ignition Control Unit Plug

Wire Bale That Secures Ignition Control Unit Plug

Ignition Control Unit Removed From Plug

Ignition Control Unit Removed From Plug

The cable with the ignition control unit plug has a large white plug on the other end that is part of the main wiring harness. I unplug the ignition control unit sub-harness from the white plug so I can remove the main wiring harness. The other end of the ignition control unit sub-harness goes inside the engine to the ignition trigger unit beneath the front engine cover.

Headlight & Starter Relay (Left) and Ignition Control Unit Wire Bundle (White Plug) Routing (Right)

Headlight & Starter Relay (Left) and Ignition Control Unit Wire Bundle (White Plug) Routing (Right)

There is a lot of corrosion on the back of heat sink that I will clean up.

Crusty Heat Sink Of Ignition Control Unit Needs Clean Up

Crusty Heat Sink Of Ignition Control Unit

Remove Voltage Regulator Bracket

There is a black plastic plug that fits into a socket with three pins in the bottom of the voltage regulator can. I remove it. The voltage regulator attaches to a bracket on the right side of the spine tube with two Allen bolts and wave washers under the voltage regulator can. The rear Allen bolt also secures a bundle of BROWN ground wires for the wiring system.

NOTE:
The Allen bolt connection to the ground wire bundle is critical to proper functioning of most of the electrical system so it’s a good idea to check that bolt to ensure it is tight and there is no crud or corrosion that will interfere with a solid ground to the frame.

Voltage Regulator (Silver Can With Red Tape) Has A Plug With Three Wires In The Bottom

Voltage Regulator (Silver Can With Red Tape) Has A Plug With Three Wires In The Bottom That Goes Inside The Front Engine Cover

Voltage Regulator Mounts With Two Allen Bolts To Bracket On Right Side Of The Spine Tube

Voltage Regulator Mounts With Two Allen Bolts To A Bracket On Right Side Of The Spine Tube

Removing Voltage Regulator From Bracket

Removing Voltage Regulator From The Bracket

Voltage Regulator Hardware Detail

Voltage Regulator Hardware Detail

Main Wiring Harness Ground Wires Secure To Voltage Regulator Rear Mounting Bolt

Main Wiring Harness Ground Wires Secure To Voltage Regulator Rear Mounting Bolt

Ground Wire Bundle Routing From Main Wiring Harness

Ground Wire Bundle Routing From Main Wiring Harness

Remove Headlight & Stater Relay Sockets

The headlight relay and starter relay plug into separate sockets attached to a bracket on the right side of the spine tube. The GREEN wires attached to the ring terminal are not stock. They bring power to the auxiliary relays mounted on the top of the voltage regulator bracket in front of the headlight and starter relay bracket.

Headlight & Starter Relays, Sockets and Mounting Bracket On Right Of Spine Tube

Headlight & Starter Relays, Sockets and Mounting Bracket On Right Of Spine Tube

Non-Standard GREEN Wires Go To Auxiliary Relays

Non-Standard GREEN Wires Go To The Auxiliary Relays

The starter relay includes a diagram of the numbered terminals and a Bosch part number and manufacture date. It looks like the original starter relay was replaced. The terminal numbers are shown on the bottom next to the terminal.

Starter Relay Terminal Diagram-Note Diode Between Terminals 86 and 86a

Starter Relay Terminal Diagram-Note Diode Between Terminals 86 and 86a

Starter Relay Bosch Part Number And Manufacture Date

Starter Relay Bosch Part Number And Manufacture Date

Starter Relay Terminal Numbers Next To Terminals

Starter Relay Terminal Numbers Next To Terminals

The headlight relay has the terminal numbers printed on the bottom.

Headlight Relay Terminal Numbers Next To Terminals

Headlight Relay Terminals Numbers

Remove Auxiliary Relays and Socket

It’s easier to remove the auxiliary relay socket after removing the headlight/starter relay socket. The auxiliary relay socket attaches to the top of the voltage regulator bracket with two screws. I remove the relays to get access to the screws. The relays are the same Bosch part number and are 5-terminal relays with two (87) terminals.

Pair Of Identical Auxiliary Relays Mounted On Top Of Voltage Regulator Bracket

Pair Of Identical Auxiliary Relays Mounted On Top Of Voltage Regulator Bracket

Auxiliary Relays Bosch Part Numbers Are The Same (0 332 014 113)

Auxiliary Relays Bosch Part Numbers Are The Same (0 332 014 113)

Auxiliary Relay Socket Is Secured By With Two Screws

Auxiliary Relay Dual Relay Socket Is Secured With Two Screws

Auxiliary Relay Socket Hardware Detail

Auxiliary Relay Socket Hardware Detail

Auxiliary Relay Terminals Are Numbered Next To The Terminal

Auxiliary Relay Terminals Are Numbered Next To The Terminal

Auxiliary Relays and And Socket, Bosch Part# 3 334 485 008

Auxiliary Relays and And Socket, Bosch Part# 3 334 485 008

Remove Turn Signal Relay

The turn signal relay socket mounts to underside of the headlight/starter relay bracket with the same screw used to secure the headlight and starter relay sockets. The turn signal relay is missing on this bike. The wires to the relay socket come from the main wiring harness.

Turn Signal Relay Socket Mounting Detail

Turn Signal Relay Socket Mounting Detail

Turn Signal Relay Socket Mounts Under The Headlight/Starter Relay Bracket

Turn Signal Relay Socket Mounts Under The Headlight/Starter Relay Bracket

Turn Signal Relay Wire Routing

Turn Signal Relay Wire Routing

Remove “Special Equipment” Plug

This plug fits into a bracket on the right side of the spine tube and has a cover over the terminals. It has two tabs that secure it in the hole. Like I did for the handlebar combination switch plugs, I press on one tab and push that end of the plug past the edge of the bracket and repeat that for the other tab.

"Special Equipment" Plug Socket Socket

“Special Equipment” Plug Socket Socket

"Special Equipment" Plug Has A Black Cap

“Special Equipment” Plug Has A Black Cover

"Special Equipment" Socket Has Small Tabs On Two Left and Right Side Of The Socket

“Special Equipment” Socket Has Small Tabs On Left and Right Side Of The Socket

Remove Fuse Box

The fuse box is attached to the rear end of the spine tube with a large hose clamp. The power into the two fuses are on the left and the power out of the fuses are on the right. There is a thumb screw on the back of the fuse box that secures the cover.

Fuse Box Cover Secured With Thumb Screw

Fuse Box Cover Secured With Thumb Screw

Fuse Box Wiring Comes From Main Wiring Harness

Fuse Box Wiring Comes From Main Wiring Harness

Fuse Box Wiring Detail

Fuse Box Wiring Detail

The wires on the left side of the fuse box are GREEN on top and GREY on bottom. These bring power into the fuse.

Before Fuse Wires (GREEN-Top; GREY-Bottom)

Before Fuse Wires (GREEN-Top; GREY-Bottom)

The wires on the right side of the box are after the fuse. They are GREEN-Black on top and GREY-Black on the bottom.

After Fuse Wires (GREEN-Black-Top; GREY-Black-Bottom))

After Fuse Wires (GREEN-Black-Top; GREY-Black-Bottom)

Fuse Box Removed Showing Hardware And Fuse Details

Fuse Box Removed Showing Hardware And Fuse Details

Removing Wiring Sub-Harnesses

The main wiring harness attaches to several sub-harnesses that I remove.

Clutch and Brake Switch Sub-Harnesses

The handlebar clutch and front brake switches each attach to a sub-harness. The sub-harness plugs are behind the steering stem under the spine tube. The front brake switch has a GREENRed and BROWN ground wire and the clutch switch has a BROWNYellow and BROWN ground wire. Each sub-harness routes through the hole on top of the steering head gusset on the corresponding side the switch is on (clutch-left; front brake-right). I disconnect the sub-harness plugs and remove the sub-harnesses.

Black Front Brake Switch Sub-Harness Plug and Clutch Switch Plug Behind Steering Stem

Black Front Brake Switch and Clutch Switch Sub-Harness Plugs Behind Steering Stem

Clutch Lever Switch (Broken)

Sub-Harness Plug

Clutch Switch Sub-Harness Routing

Clutch Switch Sub-Harness Routing

Handlebar Brake Switch Sub-Harness Wires

Handlebar Brake Switch Sub-Harness Wires

Front Brake Switch Sub-Harness Routing

Front Brake Switch Sub-Harness Routing

Front Brake and Clutch Switch Sub-harnesses Removed

Front Brake and Clutch Switch Sub-harnesses Removed

GEN Light And Starter Solenoid Sub-Harness

Next to the clutch and brake light switch sub-harness plugs is a large white plug with a BLUE and BLACK wire. The BLUE wire comes from the GEN light in the tachometer and goes to the voltage regulator and diode board. The BLACK wire goes to the starter solenoid inside the top engine cover. I disconnect it.

White Plug With BLUE (GEN Light & Voltage Regulator) and BLACK (Starter Solenoid) Wires Go Inside Front Engine Cover

White Plug With BLUE (GEN Light & Voltage Regulator) and BLACK (Starter Solenoid) Wires Go Inside Front Engine Cover

Neutral & Oil Pressure Switch Sub-Harness

A black plug near the left, rear of the frame connects the neutral and oil pressure switches sub-harness. The sub-harness routes along the lower left frame tube and is secured with several tie wraps.

The oil pressure switch is on the lower left side of the engine block behind the cylinder and has a BROWNGreen wire. The neutral switch is on the bottom of the transmission and has a BROWN-Black and BROWN ground wire. Due to the amount of oil around it, it’s clear the neutral switch leaked for awhile.

There is a ring terminal on the sub-harness that attaches to the lower left transmission mounting bolt to provide the ground for the neutral switch. I use a cut-off 8 mm Allen wrench to remove the transmission bolt as there is minimal clearance.

Clutch & Oil Pressure Switches Sub-Harness Plug

Clutch & Oil Pressure Switches Sub-Harness Plug

Oil Pressure & Clutch Switch Wire Routing Along Lower Left Frame Tube

Oil Pressure & Clutch Switch Wire Routing Along Lower Left Frame Tube

Oil Pressure & Clutch Switch Wire Routing Along Lower Left Frame Tube

Oil Pressure & Clutch Switch Wire Routing Along Lower Left Frame Tube

Oil Pressure & Clutch Switch Wire Routing Along Lower Left Frame Tube

Oil Pressure & Clutch Switch Wire Routing Along Lower Left Frame Tube

Oil Pressure Switch Location On Lower Left Of Engine Block

Oil Pressure Switch Location On Lower Left Of Engine Block

Neutral Switch Location Under Transmission-Well Lubed :-)

Neutral Switch Location Under Transmission-Well Lubed 🙂

Location of Clutch Switch Ground Wire On Lower Left Transmission Mounting Bolt

Location of Neutral Switch Ground Wire On Lower Left Transmission Mounting Bolt

Cut Down 8mm Allen Wrench

Cut Down 8mm Allen Wrench

Removing Lower Left Transmission Bolt

Removing Lower Left Transmission Bolt

Transmission Bolt Ground Wire Detail

Transmission Bolt Neutral Switch Ground Wire Detail

Remove Rear Lights Sub-Harness, Rear Turn Signals and Taillight

There is a large plug near the battery that connects the main wiring harness to the rear lights sub-harness. There is also a (+) battery wire in the main wiring harness with a ring terminal that goes on the (+) battery terminal along with the (+) battery wire that goes to the starter solenoid. My wire is missing the ring terminal.

Rear Lights Sub-Harness Plug and Main Wiring Harness (+) Battery Wire (Missing Its Ring Terminal)

Rear Lights Sub-Harness Plug and Main Wiring Harness (+) Battery Wire (Missing Its Ring Terminal)

Rear Lights Sub-Harness Plug

Rear Lights Sub-Harness Plug

The rear lights sub-harness routes along the left rear sub-frame tube and is secured with tie wraps.

Rear Lights Sub-Harness Routing

Rear Lights Sub-Harness Routing

The rear light sub-harness wires go to the rear turn signals and to the rear tail light assembly. The turn signal wires thread through the rubber turn signal stalk through a hole next to the mounting bolt.

Rear Lights Sub-Harness Routing

Rear Lights Sub-Harness Routing

Left Turn Signal Detail-Wires Go Through Hole Next To Mounting Bolt

Left Turn Signal Detail-Wires Go Through Hole Next To Mounting Bolt

Right Rear Turn Signal Detail

Right Rear Turn Signal Detail

I remove the turn signal lens to get access to the reflector. The turn signal wires attach to terminals on the back of the turn signal reflector. I remove them and pull the turn signal wires out of the hole next to the mounting bolt of the rubber turn signal stalks.

Wiring Terminals On The Back Of The Turn Signal Reflector

Wiring Terminals On The Back Of The Turn Signal Reflector

Pulling Rear Turn Signal Wire Through Hole In Rubber Stalk

Pulling Rear Turn Signal Wire Through Hole In Rubber Stalk

Rear Turn Signal Wiring Pulled Through Rubber Turn Signal Stalk

Rear Turn Signal Wiring Pulled Through Rubber Turn Signal Stalk

The turn signal housing attaches to the rear turn signal stalk with a clamp inside the housing. I loosen the bolts and slide the turn signal housing off the stalk. Then I remove the turn signal stalk mounting bolt to remove the rear turn signal stalks.

Clamp Securing Turn Signal Hosing To Stalk

Clamp Securing Turn Signal Hosing To Stalk

Rear Turn Signal Stalk Hardware Detail

Rear Turn Signal Stalk Hardware Detail

Rear Turn Signal Stalk Removed

Rear Turn Signal Stalk Removed

The taillight housing is already removed from the fender as I had to remove the rear fender to get the bike into my son’s truck to bring it home. The taillight housing mounts with two bolts and lock nuts to tabs on the rear sub-frame below the seat lock.

Taillight Housing Removed From Rear Sub-Frame

Taillight Housing Removed From Rear Sub-Frame

I remove the two screws securing the lens to get access to the reflector. I remove the wires from the terminals on the rear of the reflector. Then I use a small screw driver to push the rubber grommet out of the housing to remove the taillight wires.

Wiring Terminals On The Back Of The Tail Light Reflector

Wiring Terminals On The Back Of The Tail Light Reflector

Removing Tail Light Housing Rubber Grommet

Removing Tail Light Housing Rubber Grommet

Removing Tail Light Housing Rubber Grommet

Removing Tail Light Housing Rubber Grommet

Rear Lights Sub-Harness Removed From Tail Light Housing

Rear Lights Sub-Harness Removed From Tail Light Housing

Remove Rear Brake Light Switch Sub-Harness And Switch

The rear brake light switch sub-harness plug is on the right side of the spine tube near the battery.

Rear Brake Light Switch Sub-Harness Plug

Rear Brake Light Switch Sub-Harness Plug

The sub-harness is secured with tie wraps and routes down the right rear frame tube, over the top of the swing arm and under the swing arm gusset to the rear brake light switch that is mounted on a tab on the bottom of the frame’s swing arm bracket.

Rear Brake Light Switch Sub-Harness Routing

Rear Brake Light Switch Sub-Harness Routing

Rear Brake Light Switch Sub-Harness Routing

Rear Brake Light Switch Sub-Harness Routing

Rear Brake Light Switch Sub-Harness Routing

Rear Brake Light Switch Sub-Harness Routing

Rear Brake Light Switch Mounts On Tab Of Frame Swing Arm Bracket

Rear Brake Light Switch Mounts On Tab Of Frame Swing Arm Bracket

There is a rubber cover over the top of the rear brake light switch that the wires go through. The switch is secured with two screws and the wires are attached with two pinch screws. I remove the rubber cover, the wire pinch screws, the switch retaining screws, the tie wraps, and then the rear brake light sub-harness.

Removing Rear Brake Light Switch Wires

Removing Rear Brake Light Switch Wires

Removing Rear Brake Light Switch

Removing Rear Brake Light Switch

Rear Brake Light Switch Removed

Rear Brake Light Switch Removed

Remove Main Wiring Harness

The main wiring harness is secured to the spine tube with some tie wraps that I cut.

Removing Main Wiring Harness Tie Wraps

Removing Main Wiring Harness Tie Wraps

Here’s the main wiring harness with all the under the gas tank electrical components and sub-harnesses removed. I’m ready to remove it from the frame.

Main Wiring Harness After Removing Under The Gas Tank Electrical Components

Main Wiring Harness After Removing Under The Gas Tank Electrical Components

I pull the headlight and instrument wires through the gap between the steering head and the spine tube to remove the main wiring harness.

Pulling Main Wiring Harness Out To The Rear

Pulling Main Wiring Harness Out To The Rear

Main Wiring Harness Removed

Main Wiring Harness Removed

2 thoughts on “61 BMW 1983 R80ST Remove Electrical System

  1. Love your detailed write ups! I am missing the “fuse cover with thumb screw” on my G/S, should be the same as yours, I need to find a replacement (or spend >$60 to buy the entire fuse block!). In case you plan to toss or sell any of the electrical components, please keep me in mind 🙂 !

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