back off stop light modulator

[flutemanjohn]

I am a newbie with a k75 which I am upgrading. I put a Back Off unit in line to the brake light (it works) but now the instrument panel light flashes and doesn't go off. Back Off people say this is common with bmw. They told me that sometimes an in line resistor will solve the problem but could not give a specific . Anyone with a solution? Maybe I can just discount the panel light? But how?

[johnny]

greetings flutemanjohn...

welcome to motobrick.com...

something aints right... either the unit or the install... whats the year and model of the k75... does it have abs or cruise control...

need more info on 1 the back off unit 2 where you installed it 3 how you installed it 4 exactly what is flashing that does not go off... photos and links would be best...



j o

[flutemanjohn]

94 standard ,no ABS, no cruise, opened the line under the seat ( it installs in line to the light), the Back Off people say it's a common problem stemming from the light sensor. Illuminates the red warning light on the instrument panel. Four quick flashes followed by 30 sec pause repeated as long as the bike is operating. Thanks, John

[Scott_]

Sounds like the lamp monitor circuit. Not uncommon to happen either with LED lamps. With the led's, and apparently your "back-off" module, the lamp monitor circuit can't "constantly see" the lamp because of the change(lack there of) in the circuit resistance the monitor module expects to see.

There are a couple of options here. Yes the monitor circuit can be fooled with a resistor to make it think the lamp is there and ok, but then you loose the functional purpose of the lamp monitor, but still retain the testing of the brake switches.
Bypass the lamp monitor all together, I believe there is a write up in the Lieberry about how to do that for using LED's. Again giving up the intended purpose of the system, lamp testing and switch testing.

Put yourself some black tape over the dash indicator. After all, the system would be just as "non-functional" as a total bypass and not have to do any wiring.

Get yourself a different style of added illumination for the back of the bike, and leave the stock lamp wiring intact.

Just offering opinions and suggestions......  It is ultimately your ride, and up to you to decide.

[flutemanjohn]

Thanks Scott, they have another device that monitors the speedometer  and applies a brake warning when the bike decelerates. But it's more expensive and complicated to install. I may use the black tape solution temporarily (it would glow at night) and think about it further. Flutemanjohn

[flutemanjohn]

Anyone out there who knows what type of resistor would work and how to install it?

[johnny]

rodger all that...

this is the unit i have used on 3 motobricks... and dozens of other motobrickers have used for years... 100% reliable with no negative side effects...



could always sell the back off system and go with the electro flasher...

concerning the deceleration concept... following drivers stop paying attention to the flashing brake lights of the leading motobricker when no braking is occurring... then when its needed most... when braking... well... they quickly stopped paying attention long ago and bam... bam...

headlights shoulda nawt flash... ever... brake light shoulda flash a few times when braking is initiated then go steady... period...

the #1 lighting mod that can be made to a motobrick is this... electro flasher is #2... headlight relays and a good bulb #3... everything is fantasy...

j o

[flutemanjohn]

Thanks for the great info. It seems I was getting ahead of myself and should have researched more before I started making modifications. I will follow your advice. Flutemanjohn

[enb54]

I have the Backoff unit on my machine right now (installed in the brake light housing with spade connectors for easy removal) and have had no problems, but next time I'll get an electro-flash per jo's note. The electro-flash is quite a bit less expensive also...