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Kat Dash BMW /5 LED upgrade install

2018 June 9

I had a wonderful opportunity of installing a Kat Dash /5 LED kit on my customized California blue 1973 R100/5 (yes, it is a /5 with a R100 engine) .

I had the headlight apart already to tighten up the custom key assembly that started turning inside the headlight bucket when I turned the key.

A nice small, tidy box containing the kit arrived in the mail.


The bulbs are labeled nicely in baggies with stickers that indicate the bulb color. I wasn’t sure what the wiring was for and then read the directions and figured it out.

Side note – This bike has the custom key seen here (not a typical /5 nail style key) and LED turn signals that required I wire in resistors to create more  load to activate the turn signal relay.  And, I decided to adapt all the wiring to a /6 style relay board. It all makes sense to me…

But here is what the headlight bucket looked like when I opened it up (spaghetti anybody?).
The gold things are resistors I had that were wired along with the LED turn signals.
One lead of the resister was wired with the positive lead of the turn signal and the other lead of the resistor was wired with the same ground as the turn signal.

R75/5 headlight wiring with /6 Relay board

The Kat Dash kit is pretty easy.
Follow the directions.

BE CAREFUL not to twist the LED’s in the bulb housings too much.  They will come ripped out of the bulb base if you do.

A few things to realize – There are additional wires with resistors added to allow the Generator/Voltage light to activate with the LED bulb.
The same goes for the Turn Signal indicator Light.

I got half way through my install when I hit a major problem – one of the LED lights popped out INTO my speedometer!  Yikes!  This was not any fault of the LEDs.  It had to do with the bulb base being worn/bent too much to hold the bulb in place correctly.  I had to take everything apart, remove the speedometer, and spend about 10 minutes with a tiny magnet until I was able to fish the light out of the speedometer’s rear bulb housing area.

If the bulb sits crooked in the wired base, FIX it before you install it into the speedometer.

With my 4yr old’s fingers to help me with the photo, I was able to fix it with a dental pick and bend that lip out to catch the bulb better, and hold it straight in the housing… and most importantly, not eject the light into the speedometer housing!

I continued my assembly, and to my surprise, after I wired in the relay to allow for the new LED turn signal indicator bulb to work, I no longer needed my big gold resistors in my wiring scheme.
Kat had sold me an electronic turn signal relay that works with LED bulbs and I ended up not needing it.

Here is the bike off:


Bike with the LED running light on:

Bike with the LED lights on – So bright the gamut of the camera could not capture them:

And a video of everything working:

 

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