Wiring Harness Repairs

There are a couple of potential issues with the wiring harness on the F650GS which should be checked.

These issues are the subject of TSB's but too many machines have suffered damage as a result of the measures not being addressed or not completed properly by dealers when machines have been serviced. The first issue is shortness of the ignition switch wiring coupled with poor routing during assembly

The second issue is chafing of the wiring harness around the rear shock preload adjuster

In addition to the identified issues above, other chafing points have been found by individual owners. One point is behind the steering head on the RHS. It would be advisable to check the harness when servicing the machine and add self amalgamating tape where ever there are any signs of chafing.

Wiring Harnesses

There are differences in the wiring harnesses fitted to the early F650GS and Dakar models, part of the continuous improvement production system. These changes are not documented in the wiring diagrams. The production date of harnesses should be checked in any wiring harness replacement. There is also a difference in the ABS plug connections between the GS and Dakar on all the F650GS models. See the ABS page pdf files.

A pdf of the harness Part No's and known differences is here Wiring Harness pdf

There are Diode Relay wiring variations on 2000-01 harnesses 2000-2001 Diode Relay

Ignition Switch Wiring

The ignition switch on some machines was routed poorly during production and can be stretched on full lock. This can lead to stretching of the wiring and potentially shorted wiring. In some cases chafing of the harness can occur. There is a TSB covering this issue & dealers were to check it during pre delivery or servicing.


Carefully check the routing of the cable from the ignition switch

Ensure the wiring is not tight on full lock.

Check the wiring for any signs of chafing.

Re route the cable if it is tight in any way.

Ignition wiring repair pdf from f650.com Ignition Wiring Repair pdf

A pdf of ignition switch de-assembly from f650.com Ignition Switch Repair pdf

Indicator/Hazard Switch Wiring

Sertao owners have reported some wire chafing around a sharp corner on the top left radiator mount. There are also reports of chafing of the wires to the front indicators against the fairing bracket particularly after a fall or aging/breaking of the indicator mounts.

The chafing can cause the hazards randomly turn on or blowing the fuse. Well worth checking when undertaking maintenance and possibly re routing cables.

On models with hazard switch when fault finding remove the 2 hazard switch relays in the electrical box, The hazard system is an overlay to the indicator system which supplies power after the ignition is turned off. When the relays are removed the indicators operate as normal but with the 3 diodes in circuit, test the diodes, resolve any wiring issues then install the relays to test hazard operation.

Shock Adjuster Wire Harness Chafing

The wiring harness can chafe on any rough surfaces of the rear of the shock absorber preload adjuster. There are a number of instances of wiring fires as a result of the chafing. One machine caught fire while parked in the street, another when parked at night in a camping ground and one when riding on a freeway. Others have encountered electrical faults which have been traced to chafing of the harness causing shorting of the wiring.

The chafing points are at the top and bottom of the adjuster bracket and further up at the engine mount.

See NTSA TSB No 10029188, BMW TSB No TB-61-002-08

Remove the Preload adjuster from the mounting bracket and remove the adjuster bracket from the frame. Ensure there are no rough spots or edges on the bracket.

Wrap the harness with additional self amalgamating tape.

Use cable ties to secure the wiring harness.

Radiator Wire Harness Chafing

The wiring harness chafes on the top of the radiator, the pic on the left shows damaged wiring

Repair wires and rewrap the harness as per the pic on the right.

Wiring Loom Amalgamating Tape

Traditionally either impregnated cotton tape or a plastic adhesive tape has been used to wrap wiring harnesses.

The modern alternative to these tapes is a silicone self amalgamating tape which is used in aircraft wiring looms.
It is commonly called rescue tape. See RescueTape.com for details and specifications.

Wiring Fire and Chafe Images