Horn / Dimmer Switch / Airheads '75-'78

Faithful reproduction of the no longer available Horn/Dimmer switch for 1975-1978 BMW motorcycles. Compare to BMW 61 31 1 243 731. The 22” long wiring harness was designed to fit all model handlebars including S bar, RS bar, standard USA bar or even the RT length bar (for models with lower handlebar simply pull excess wiring into headlight bucket).

Color coded wiring so it plugs in just like the original.

Wiring connectors are similar to original with correct 90 degree or straight ends as applicable covered with clear insulating boots.

Wiring harness loom and grommet designed to match the original switch.

Two year warranty.

Yes these switches are expensive, that’s because they were expensive to make. The original switches from BMW were not cheap either, and now you can’t get them. We’re lucky to have these excellent reproductions available in the marketplace.

A little bit of backstory to help clarify. BMW discontinued the original /6 switch a long time ago, replacing it with the /7 switch. Whenever you ordered a replacement left switch for your 1975-1976 /6 model from BMW, you were sold the /7 switch. Now that the /7 switch is no longer available, this repro switch was made to replicate the /7 switch, and it also fits the /6. 

Years ago when we started installing /7 switches on /6 models, we were informed by BMW that the red wire was discontinued because they saw no need for the "press to flash" function to work when the key was in the off position. So they deleted the red wire from the /7 switches so you could only “flash to pass” when the key was on. 

The brown wire (which was deleted from the /7 switch) was for the horn on a /6 which has constant positive voltage, it just needs a switched ground to activate. But for /7 models, the horns are self-grounding so the horn needed voltage only, that is the green wire with black stripe on the /7 switch. Both go to the horn button. Therefore the green/black wire needs to send a ground to your horn on your /6, so you put the green/back wire from the switch on the brown section at the bottom of your contact plate in the back of the headlight on /6 models, but it needs to send 12 volts positive for /7 so the green/black from the switch goes to Green/Black on /7 models. 

Here’s the wiring scheme for the new switch, eight wires in total: 

(Red wire and brown wire from old /6 switch were deleted). 

Yellow/White wire to #87 on headlight relay 

White wire to White section of Contact Plate 

Yello wire to Yellow section of Contact Plate 

Brown/White wire to Brown/White section of Contact Plate 

Green/Black wire to Brown section at bottom of Contact Plate for /6 models, to Green/Black on Circuit Board on /7 models. 

Green/Violet wire to terminal 86 on Headlight Relay 

Grey wire to Grey section of Circuit Board 

Green wire to terminal 56 on Ignition Switch