2022 Drake Smith - Please do not use or reproduce this elsewhere.  Feel free to link to it though.

K Bike Relay Box Layouts & Relays

Block Diagram

Socket Pinout

(Click thumbnail to enlarge)







Flasher Relay

(All Ks)

Bulb Monitor Unit (BMU)

(All Ks)

Temp/Fan Relay/Switch

(K75 & 2V K100 only)



Load Shed Relay:

When starting, the load shed relay cuts the power supply to several circuits so that more battery power is available for starting. For example, on a K75 or K100 the load shed relay cuts power to the following circuits when the starter motor is engaged:

  • Headlight

  • Temperature/radiator fan relay

  • Horn relay

  • Flasher relay

  • Connector for optional alarm system


K100(2V) & Early K75 Relays:

These Ks have three relays at the front. The two on the right are the horn and load shed relays. They are the same relay and interchangeable for testing purposes. BMW part 61311373585 or 61311373588. For very early Ks they are yellow, for later Ks they are light blue in color but function identically and are interchangeable.

Although these are similar to generic 4 pin normally open automotive relays, the 30 & 86 pins for the K bike relays are Type A configuration while with most generic relays the 30 & 86 pins are Type B configuration.

Early Fuel Relay:

The relay in the front left is the fuel injection relay. BMW part 61368373700. This relay is used in many vehicles and available elsewhere as a Tyco V23134-K59-X312.

The original factory fuel relay is black:


The one that BMW currently sells is light green:


Later Relays:

Late K75/100s as well as K100RS4V, K1 and K1100 bikes use small black 4 pin normally open relays. BMW calls them Mini Relays while Bosch calls them Micro Relays. BMW part 61311459677.

85 - Coil Trigger Ground

86 - Coil Trigger 12V

87 - Output

30 - Input

Used for:

K75/K100 K100RS4V, K1, K1100
Load Shedding Load Shedding
Horn Horn
Fuel System Fuel System
  Radiator Fan
  Motronic Control Unit

ABS Relays:

The ABS Safety Relay is used on ABS I K bikes. It powers the ABS modulators. BMW part 61311459676. (On ABS II K bikes this relay function is built into the ABS control unit.)

The ABS Warning Relay is a micro relay used on both ABS I and ABS II bikes. It illuminates the ABS warning lights in the instrument cluster. It is a normally closed relay and is not interchangeable with the black 677 relays. BMW part 61311459675.

Windscreen Relays (K75RT & K1100LT):

The two (up and down) electric windscreen relays (BMW # 61361393415) are not in the relay box. They are gray 5 pin micro relays mounted on the fairing bracket up under the windscreen assembly on the right side.



2022 Drake Smith - Please do not use or reproduce this elsewhere.  Feel free to link to it though.