Miscellaneous Electrical Q's for the GS/Dakar
compiled & edited by Kristian #562
Please read the Disclaimer before attempting any work in this FAQ.

What is the Capacity of the Charging System

Let's see, that's your key in your hand, but your bike is trying to start?

edited by Adam #1001
August 19, 2000

Well it seems to be a problem with the first F650GS's released from BMW, and it appears to be world wide. However, there have been no reports about this problem from anyone in USA yet.

According to BMW, the starter relay fuses together due to low voltage in the battery. When this happens the starter is continually engaged and will continue to try an start until there is not power left in the battery. Some folks will find this problem reminiscent of the early K bikes.

If you encounter this problem, you must do something immediately, since the starter is not designed for continuous load, and possibly might be damaged. You'll find the relay under the tank dummy cover, in front of the battery. To get access to it, you have to remove the cover. Once you have removed it, hit the relay with a screwdriver or something similar, then there should be silence. If not, remove the battery's ground connector and call the local BMW service number. In any case, you should make your dealer order and mount a new relay. It's a case of warranty, and it should cost you nothing.

The only thing you can do to prevent this is to keep you battery charged. Don't lug the bike around town. Basically keep the RPM's up so the battery is getting a charge. You may even want to consider the Battery Tender that has the BMW Accessory connector on it so you can charge you bike while your not riding it.

Addendum 10/1/00

It has come to our attention that BMW has new starter solenoids that will not fuse the starter relays. This is suppose to be covered under warranty and a recall is suppose to be announced for all countries with the new GS and Dakar except the USA (They have their own problems).

Adamx 1001: my GS had a faulty one in November 2001, so there's still a few problems.

Where Is That Connector the Heated Grips Attach To on a GS?
Aaron Wallace
April 16, 2001

I recently installed the factory heated grips on an 01/01 production F650GS with ABS. On my bike, the small wiring harness included with the kit that goes from the fuse box area near the front of the seat to the junction box in front of the battery was already installed--thus why I couldn't find the spare connector to plug the harness included with the kit into. The diagrams included with the instructions are vague here, so I wasted a fair amount of time searching in vain for this connector.

The connectors that the grips and switch attach to were buried in the wiring junction box that's between the battery and the front of the frame, in front and under the more visible connectors in this area. I couldn't see them, and had to fish them out by reaching around for them.

I'm not sure if having this wiring already in place makes installation that much easier--it may be possible to get by with removing only the part of the airbox that's in front of the air filter (which would be good since getting the airbox seated fully on the throttle body isn't easy), but you still need to remove the three painted panels, the battery, part of the airbox, and the cover to the junction box.

Oh, and you need to install a 7.5A fuse in the bottom slot to use the grips. The kit doesn't include one, but the factory toolkit does :~)


Does the F650GS BMW accessory socket kit fit a Classic?
by Harl #380

The GS/Dakar kit is different from the Classic kit. The Classic kit connects to the battery directly while the GS kit connects to a plug on the wiring harness. The socket mounting is different as well.



Heated vest and BMW accessory plug installation

by rpozak (Rod CO '02GSA)

Tired of freezing my kahunas off here in CO this winter, I got a heated vest and bought the BMW accessory plug. As usual the BMW instructions made me want to throw something.

  1. Note that I use the word “clip” to denote a mechanical fastening device and the word “connector” to denote an electrical connecting device. This is very important.

  2. Take all faux tank panels off. It will be a lot easier. Refer the Fairing FAQ GS.

  3. Install the accessory plug on the left side of the bike as described in the BMW instructions that came with the kit. I plugged-in the wiring harness to the accessory plug first, and bolted the plug to the bracket first since it looked like h*ll to do it after the thing is bolted to the bike. Two screws and some careful wire routing and you are done. Now sit back and wonder how you will plug and un-plug things without messing-up your clutch cable.

  4. Route the wires from the new accessory plug to the right side of the bike. It is now time to toss the BMW instructions since they are 110% worthless from here on out. Trust me.

  5. Slip the black fuse box (right side under seat near end of faux tank) off of its holding clip. You will have to push the little tab on the clip, otherwise you can pull with all your might and it will not slip off.

  6. Locate the accessory connector on the right side of the bike fastened by a little screw to the inside (closer to the engine) of the stamped metal frame-like part (painted black). You will see a white connector and a blue connector “clipped” together. Leave the blue one alone as there is no telling what it does.

  7. Unplug the female end of the white connector from the male end. You have to squeeze the tabs on the side of the female end. Use both hands unless you are some kind of mutant with very long fingers.

  8. Remove the little screw holding the white and blue connectors to the black frame part. Don’t worry about getting this little screw back in; it is easy and it is the least of your problems.

  9. Cut the cable tie that goes through a little hole in the black metal frame part so the wires are loose and you can move the white and blue connectors around. Cutting this cable tie is important, or you will never do what comes next – which is almost impossible anyway.

  10. With your extremely long, mutant fingers, “clip” the new white accessory plug (male end) to the side of the existing white male end connector. This is not easy my friend but it can be done. Have patience. Do what Flash does and have a Rum & Coke. Examine you wire routing first to be sure nothing rubs against a hot engine part like mine does. You should see two male connectors facing up and ready to mate with the females (connectors).

  11. Plug the white female end of your new accessory plug into the white male end of the connector closest to the blue connector.

  12. Plug the other white female end into the other white male connector closest to the engine.

  13. Put the little screw back in that holds the connectors to the black metal part, put the cable tie back on that holds wires to the black metal part, clip the fuse box back in, carefully check your wire routing (especially that brown fuse hanging from that wire there) and put cable ties where appropriate.

  14. Start her up and plug-in Christmas lights (wish I had a digital camera, but you can imagine).


Sidestand Switch Problems?

Problem 1: Side stand switch popped off
Pelle, Sweden

Riding down the road, motor just stops. Bike will start in neutral, as soon as I shift into gear, motor cuts out. I find side stand switch is jammed between, exhaust pipe and mounting stud, melted. I can still move metal part of switch to get me back on the road. What are others doing with side stand switch? Can I just cut the wires and wire together?


According to electrical diagram wires from sidestand-switch are connected:
Brown - ground (negative)
Brown/Black - gearbox-switch
Brown/Violet - Motronic-relay

Without having bike available for confirmation I believe that Brown connected to Brown/Violet is the way to wire it without the switch.

Note - There may be some discrepancy between the wire colors shown in the service diagram, and what is actually on some bikes. See below for another solution:

Ok, there are three wires: Red, Brown, White... I removed the kill switch then tried jumping the wires.... after a while I found that the White & Brown jumped will disable the side stand kill switch and allow the bike to run properly... Do Not use the RED wire IT WILL NOT WORK PROPERLY.
Wild Willy, CG# 1995 '01 F650GS, Edmonton, Canada


Problem 2: Sidestand Switch Warning
Andy Leeds UK #982

(For an 1150R) My outfit has no sidestand (it only falls over if you really try hard!) hence the switch that kills the engine if the sidestand is down is overridden. I know a few riders also do this so they can start the bike on the stand. Take care how you do it. I am assuming that the FI on the F is going to work the same way as on the R. Just ignore me if this is not correct.

The circuit looks simple. Power from the ignition switch, through the kill switch (closed= go), through the sidestand switch (closed= go) to the fuel pump relay then to the motronic unit. Looks like a simple check at the side of the road, no fuel pump at ignition on, you check the continuity. If there is a circuit, check the relay. If the relay is OK, its the pump, so call the RAC (Pick-up van.)

Not correct! The motronic unit seems to back feed about 1.5 volts down the line to the relay when the ignition is on and the switch is open and/or as the unit shuts down. This needs to be overcome by the power coming the other way to get the relay to close and give you the fuel pump function if you close the stand switch after ignition on. If your sidestand switch or sidestand switch bypass wire is not perfect (mine had water in the connector) this is taken as sidestand down, so the bike won't run.

When checking, you need to pull the plug off the stand switch, jump the pins with thick wire then check there is zero current until the ignition is keyed. At this point when the ignition is keyed, if that's the problem the fuel pump will prime.

Three hours at the side of the road, on the truck and in the garage, all because a 2 pence connector let in water and Bosch have some weird features in the electronics! I think the back feed is a test signal that allows the unit to log different faults for sidestand down, side stand failed open circuit or to ground, relay open circuit or failed to ground (useful if you can read the memory).

On the up side, the RAC orange van guy seemed to know something about FI, his mate that he phoned knew BMW bikes and the recovery guy knew how to fasten it down safely. Good service IMHO.

GS Horn stopped working?

For Aftermarket Horns and Horn Installation Tips see the FAQ

Symptoms: My 650GSA's horn has stopped working. I press the button, and no honk. I've checked the fuses, and they all look fine. So, now I fear it's going to entail pulling off body panels to trace the wiring in the middle of my apartment parking lot. So, before I start pulling pieces off, I figured I'd see if anyone had any suggestions as to where to look specifically for electrical problems? I figured a good place to start would be the horn itself. Everything else on the bike is working just fine, so I'm thinking it might just be a problem with the horn itself, but I'm not sure.

Mystery Wires?

Q. I have come across an embarrassing problem. I recently had to disassemble the rear frame, including disconnecting all the wires. But I did not pay enough attention to the set-up before I started. I have now completely re-assembled the rear frame but I have 2 loose wire connectors (coming from the main frame) that don’t seem to go anywhere! They are just lying there right next to the fuel pump underneath the seat. The bike seems to be running fine without them being hooked up anywhere (I have checked all lights, ABS, etc.) Are these just duds that are there for accessories and the like or do they actually go somewhere that I have overlooked? Please check under your seat and tell me you have those lose wires there as well! I have the 2002 Dakar w/ ABS brakes, Australian model.

One of them is a flat white connector (I think it has 4 'prongs' inside the connector). Looks like some kind of main power lead. The other one is black and is more fancy with the little wire spring to hold it in place when connected. This one looks like it is for electronics rather than power.

A1. One may be a service port. My ABS equipped GS has the large square-shaped connector with the spring. 1 Green wire, 1 Gray/ yellow. It is not in use on my bike and not sealed of from the factory- now it is sealed. Haakon #626(Norway-F650GS).

A2. The other may be a connector for Heated Grips


Q. Spare electrical connection. I have just dismantled my 2001 GS to measure valve clearances and upon reassembly I noticed a short (perhaps 2 inch ) electrical cable c/w a 2 round female plastic connector coming from the harness that powers my fan. In fact the connector is located directly above my fan. I have doubled checked and cannot find a spare male connector within the short cable distance, so I just continued on and buttoned every thing else up and she fired up no problems. Does anyone else have this spare connector? No voltage, however 10 Ohm resistance, brown cable and white with a blue trace cable.

Thanks for making me look again, sure enough I couldn't see for looking I found the other end for my missing connector I was looking for a flexible wire and connector and there in front of me fixed to the fan body was !!!!. Sorry for the run-around and thanks for the help.

Mystery (unused) Connector Under Seat?


On my 2002 Dakar there is an unused connector under the seat... It's in this pic



You can see it with the red circle... what is this connector? My bike has ABS but not heated grips... could be this for optional heated grips? zippo

Short Answer: We don't know. If you find out and have it very good authority, let us know!

Electrical Junction Box or Connector?


Q. Does anyone make some type of junction box where you can get power from the battery at an easy place? It is a PITA to keep going to the battery under the plastic to get a power source for accessories like additional lights, radar, GPS, heated gloves, communicators and the like.

A. Down on the right side (when on the bike) if you take off the body panel you will find a junction box. This is where you plug in your BMW headed grips and accessory socket. It was an expandable connector. You can daisy chain multiple add-ons together to build a big chain. The connector is a PITA to get to tough as it is behind the frame. (It is anchored to the inside of the frame by a screw).

What is that "Faux" Button beneath the Cut-off Switch

Charging Problems

by Haakon #626

The connector for the generator output, VR input, had a distinct green, copper oxide, color inside despite me filling it with dielectric grease just a year ago! The connectors are behind the small plastic "cover" at the bottom of the cylinder, right- hand side.

As a preventive action I cleaned ALL connectors with contact cleaner and a toothbrush/ cotton wads and then used CRC 6-66 all over (a SPECIAL type developed for boat use), before I filled the connectors up with di-electric grease. The VR contacts had NOT been cleaned properly before I used the grease so I guess some water was "trapped" inside the connector. The contacts that has been given the full treatment is nice and clean!

See also (Classic) Voltage Rectifier FAQ but the symptoms of failure are the same. Failures haven't happened on the GS/Dakar (yet) though!

Garage Door Opener Installation

from bbb986s
silver/black '03 F650GS.

Based on a post from another forum this is a simple hack to have a convenient pushbutton switch available for your garage door opener. I placed the switch in a place where rain is less likely to get to it.


Remove 3 screws to take off the silver shroud surround on the instrument cluster

Remove 3 screws to take off the bug screen, then take out the 2 plastic screws with the expansion sleeves

Remove the rear two screws on each side so that the black plastic surround will come out. It removes very easily

Remove the black plastic surround

Black plastic surround removed

Radio Shack momentary pushbutton switch

You will need to drill a 1/2 inch hole

Drill a pilot hole first. Then, drill progressively larger holes until you reach 1/2 inch diameter. Be careful, the front of the plastic is very soft and scratches easily.

Consider covering it with some some clear packaging tape or drilling from the back instead of from the front.

You end up with a 1/2 inch hole. Take your time, don't make any mistakes.

Micro sized Genie garage door opener fits well. You might be able to use the slightly larger mini size instead. This one has three buttons, I used only one. For those of you inclined towards symmetry, drill another hole and wire up an additional switch.

Open the garage door opener and solder some light gauge wire to either end of the switch of your choice. Switches are typically marked S1, S2, S3 on the circuit board. It was easiest here to solder on the back of the board.

Completed. I used a Dremel to drill out the plastic case for the wire to exit. A little bit of hot glue filled in the gap.

This is Performix "Plasti Dip" spray on rubber coating. "Plasti Dip" covers the exposed wires. I've never used it before, it's a spray on rubber coating that does the same thing as electrical tape although you'll need several coats and some patience to allow it to dry.

First time I've tried this stuff. The switch itself is not waterproof. Not a big deal for me, but if you spend a lot of time in heavy rain maybe you can come up with a solution. Use at least a couple of coats to get good coverage

The wire from the switch to the garage door opener is only about 1 foot long

That is more than enough.

 Slack is bundled up with a nylon tie. Oh, and this is from the "Read all directions first" manual, RUN THE WIRE FROM THE OPENER THROUGH THE BLACK PLASTIC SURROUND AND THEN TO THE SWITCH BEFORE SOLDERING!!!

The micro sized garage door opener easily fits in the available gaps

Garage door opener is tucked back behind a tubular bar

Almost done

Almost done

Silver cover reinstalled


Black switch is stealthy
Use Radio Shack part 275-646 (red button instead of black) if you want everybody to ask you "what's that red button for?"


Could install another switch on the left if you need it