1977 BMW R100RS Electrical System Functional Test

[@BarneyHaynes-s8l]

Not that I am aware of. I bought it off a friend who bought it new. Given it's the original loom, its unlikely. The only changes to the wiring were extensions to fit a Rickman Polaris fairing which has been off for years and the bike has been running well since then. I have changed the flasher relay but that was a straight swap......

[@BarneyHaynes-s8l]

Hi Brook, I have a 1979 R80/7 which I have owned since Aug 1979. The wiring appears to be all factory but I have a little problem. There is a brown/black wire attached to the horn circuit which shows continuity, as best I can tell, to the neutral switch circuit which is also brown/black. The brown/black wire attached to the horn does not appear on any wiring diagram I have seen and I cannot understand what purpose it serves. Do you have any ideas?

[@BrooksAirheadGarage]

Barney, According to the Haynes wiring diagram, the horn should be connected to a BROWN-White wire, not a BROWN-Black wire. The BROWN-Black wires go to the neutral switch circuit.

[@BarneyHaynes-s8l]

Yes, I know but there is a second wire attached to the horn connector on the contact board which is brown/black as well as the brown/white. The second wire, the brown/black, does not appear on the Haynes diagram.​@BrooksAirheadGarage

[@BrooksAirheadGarage]

@@BarneyHaynes-s8l So someone hacked the wiring for some reason. The BROWN-Black should be on terminal "85b" and BROWN-White single wire should be on terminal "H". It's possible someone added a second horn wire but didn't use the correct wire color code, or for some reason added the BROWN-Black neutral switch wire to the "H" terminal.

[@sams8798]

Hi - i am working on a r100 rt , i am having trouble with starting the bike. All the lights work on the dash but when push the green start button nothing is happening . i put a brand new battery , looks like no power to starter motor, or starter relay or some thing else i don't know. pls advise . thanks rd

[@BrooksAirheadGarage]

Hi Sam, It does sound like the starter relay, starter solenoid, starter motor or wiring to/from the starter relay to the starter solenoid may be at fault. Using a volt meter, you should trace power to the starter relay and out of the relay, to the starter solenoid and out of the starter solenoid to help you identify the cause. You should get a wiring diagram to help you with this. I have published wiring diagrams and for the /5 and /6 bikes, but not the /7 series which includes the RT on my site, brook.reams.me/bmw-airhead-motorcycle-electrical-systems/. The Haynes and Clymer manuals have diagrams, although they do have some errors here and there, they can help you trace the wiring.

[@sanchezjaime2348]

Hi . My 86 r80rt full on headlight it's not working. But flasher does. Thanks

[@BrooksAirheadGarage]

Hi Jaime, The headlight uses the low beam filament when the ignition is on. The flasher uses the high beam filament. It's possible the low beam filament in the headlight bulb is burned out. It's also possible that the yellow wires that send power to the low beam are loose. I'd check these areas and see what you learn.

[@sanchezjaime2348]

@@BrooksAirheadGarage thank you so much. I will check that

[@sanchezjaime2348]

Everything looks good. Do you think can be the switch control?

[@BrooksAirheadGarage]

@@sanchezjaime2348 Yes, it could also be a failure in the switch.

[@59jaguar]

I am installing a s fairing in my r90/6 and Would like to know if It’s possible to have another gauge in lieu of clock? Gear selector or a fuel gauge perhaps ? Thoughts if possible ? Thanks again

[@BrooksAirheadGarage]

Hi Rodger. You can put anything you want into the dash so long as it fits the hole and the rest of the instrumentation (sending unit, wiring, etc.) can be adapted to fit the bike. Some common add-ons are cylinder head temperature, oil temperature, oil pressure, etc.

[@59jaguar]

@@BrooksAirheadGarage thanks for clarity on gauges . I miss not having a gear selector or individual blinker lights on the dash . Thanks Did you happen to do a video on installing a dyna ignition on a r bike ?

[@59jaguar]

@@BrooksAirheadGarage did you have a video on installing a dyna ignition?

[@BrooksAirheadGarage]

@@59jaguar No. But I do have documentation on installing it on my web site. The material also covers adjustments to the ignition for dual plug heads. --> 12 BMW 1977 R100RS Install Dyna III Electronic Ignition-Refurbish Automatic Timing Unit (ATU) [brook.reams.me/bmw-motorcycle-rebuilds/1977-bmw-r100rs-rebuild-project-index/12-bmw-1977-r100rs-install-dyna-iii-electronic-ignition-refurbish-automatic-timing-unit-atu/] --> 12 BMW 1977 R100RS Changes To Ignition For Dual Plug Heads [brook.reams.me/bmw-motorcycle-rebuilds/1977-bmw-r100rs-rebuild-project-index/12-bmw-1977-r100rs-changes-to-ignition-for-dual-plug-heads/] I hope that helps.

[@fe6646]

I’m looking to upgrade the ignition system on my r100rt, how do you like your dyna?

[@ridakikkoobrida9219]

Bon jour s v p envoiyer moi le faisceau entre la cassette et la bobin moto bmw r65 merci

[@mithunmandal598]

Very nice video Dost my KZbin channel very nice bike be