First off, I'd like to say a HUGE THANK YOU to Jerry Skeene (BMWBMW) for going out of the way to help me with mounting/wiring the lights.
Task: Mount a set of Hella FF50 driving lights on a 1999 BMW K1200 LT
Dimensions: 2 9/16"H x 4 5/8"W x 3 3/4"D
I met Jerry on Sunday 3/5 at his place in Oak Hill. Jerry and I looked at the possible mounting options. One look at the space under the fairing above the front fender and we both deided that it would not be a good idea. Jerry pointed out the amount of travel on the front forks proving that these lights would either damage the fender or break apart.
The other option we had was to mount the lights under the rear view mirrors in front of the mirror wings. Since the mirrors on the LT are the breakaway types, we had to mount the lights to the frame behind the mirrors. But as you can see below, that would be difficult to create a contour on the bracket to match the body shape.
On further inspection, we noticed a vertical bolt in the back that was attaching the fairing to the frame. That pointed a very good location for mounting the lights since it would just mean using a long bolt. It also presented a very nice and tucked in mounting for the lights.
But this mounting position also Issue#1: Should we drill a hole in the mirror housing or cut away a small clearing in order for the long bolt to pass through. Keeping mind that the mirrors need to be able to pop off when required, we decided to cut a small area of the mirror housing.
We had to go out to Sears to find M6x1.0x60 hex head bolts and spacers to mount the lights. Sears did not have any in the size we wanted, and so we went on to Lowe's. All we could find were M6x1.0x50 bolts, and 1" spacers. The other option was 75 mm long bolts. I decided to get a set of each and use the appropriate size. Jerry decided that we could cut off the extra length off the 75mm bolts if required.
The lights were test mounted, and Jerry found the 50 mm bolts to be adequate with 1-1/2" spacing.
Jerry put some masking tape on the mirror housing and marked off the piece to be cut off. After a brief tour of his workshop in the basement, which is awesome, including the neat CNC machine lathe, he used a Jewellers Saw to make the fine cut!!
After quite a few repetitions of
1. test fit the mirror housing to make sure that bolt is not touching the housing
2. Pop the mirror housing out
3. cut/file some more
4. go back to step 1
The pattern was cut adequately perfect to allow the mounting bolt to sit perfectly without touching the mirror. At the same time, we made sure that the mirror would pop out easily enough if required.
Once we had one side done correctly, we just had to repeat the same for the other side. We put the mirrors next to each other and traced a close mirror image onto the other mirror housing for another cut.
Moving on to wiring the lights, we decided to make use of the wiring that came with the lights. This was the easist since we did not have to do anything fancy (or so we thought) to get them working. I had installed a set of $20 optronics fog lights under the tip over wings and wanted to wire those as well while here.
Jerry suggested that we get a couple of identical switches to replace the mismatched switches between the fog light and driving light wiring. So, off we went to Advance Auto and brought back a couple of black switches with small red LEDs built in
The LEds illuminate when activated. We also had to get a different set of end connectors to match the switch terminals.
I went ahead and pulled out the fairing on the right side so that we could run the wires and also install the switches. Two small 1/2" holes were drilled to install the switches.
Well, after struggling with some circuitry, we finally got the lights to work.
Here's a look at the final mounting!!
Now, those are some serious driving lights!!!
and a decent set of fog lamps...
The circuit is powered from the low beam wiring and also has the switches to control them. Since the LT has both Hi and Lo beams ON when switching to the HI beam, that line is always energized whenever the ignition switch is turned ON. I wanted the ability to have multiple controls for the lights and also the ability to turn OFF all the lights when the ignition is turned OFF.
All in all, it turned out to be a pretty long tech day, but at the end we were both satisfied with the results.
Cost of all parts :
Hella Lights - $30
Other Parts - $30
Time spent installing them - priceless!!