The three pictures following were taken with the FJR on the center stand,
which alters the pitch of the bike enough to cause the lights in all three
pictures to appear to be aimed noticeably lower than they actually are, and
thus simulates the effect of moderate braking.
The picture above is of the high beam pattern. Note that the fire hydrant
is brightly lit from bottom to top, and the curbs on both sides of the road
are easily visible far beyond the hydrant. Take note also of the
depression in the road near the hydrant. Although this depression is
actually a utility access cover, it could just as easily be a road hazard
such as a deep pothole or patch of sand.
The picture above is the original low beam. The hydrant is barely visible,
the curb on the right side vanishes into the darkness just a few meters
beyond the hydrant, and the curb on the left side is hardly visible at all.
The simulated road hazard is practically invisible. Under hard braking,
the downward pitch of the bike would be much greater, and both the hydrant
and the road hazard would be in total darkness.
The picture above is the modified low beam, taken with the same or similar
exposure as the other two, as evidence by the similar brightness of the
fixed lights along the horizon. The apparent difference in color
temperature (average wavelength) is real and not the result of some error
or change in the camera settings, which you can confirm by comparing the
hue of the lights on the horizon. The color temperature is lower in this
picture because both filaments are actually being used and they are both
operating at a lower temperature. If you compare the hydrant and the curb
with the other two pictures, you will observe that the hydrant is lit from
bottom to top as it is with the original high beam, but it is lit much less
brightly than it is with the high beam. Similarly, both curbs are visible
well beyond the hydrant, in stark contrast with the original low beam, but
not nearly so brightly as with the high beam. The road hazard is much more
visible than it is when using the original low beam.
There is another significant problem with the FJR's low beam pattern, which
is not obvious in these pictures. When the bike is leaned hard in a
right-hand turn, the pattern rotates clockwise, causing the distance for
which the right edge of the road is visible to be substantially shorter
yet. Leaning the bike to the right also causes the very bright band of
light that extends outward to the left, to shine directly in the eyes of
the oncoming motorist. If the oncoming motorist can see your headlight
before you initiate the lean to the right, they will observe a sudden and
pronounced increase in the brightness of your light, and they will
naturally conclude that you have switched your lights to bright.
Part of the reason why I resolved to do something about this is because I
have been irritated by the exact same situation on the CBR1100XX, which has
a similar low-beam pattern, since 1997. If you should be of the opinion
that these problems can be effectively mitigated via simple adjustment of
the headlight aim, I assert that this is not the case. To be sure, no
matter how high the light is aimed, the low-beam pattern will still end
abruptly some distance ahead, and that distance will still be way too short
during hard braking. Furthermore, aiming the headlights higher will only
exacerbate the problem of blinding the oncoming motorist whenever leaning
to the right. This problem is very real notwithstanding that it is not a
visibility problem experienced by the motorcyclist.
At this point, I should probably digress and say something about the
technique that I use to aim the dual headlights. On a bike with a single
headlight, all one has to do is go for a ride on a straight and level road
to determine whether the road is lit best when accelerating, decelerating,
or riding at constant speed, and then adjust the aim accordingly. The dual
design makes it more difficult to gauge exactly how each light is aimed. In
order to see exactly how one or the other of the two lights is aimed, you
have to disconnect the other light. Doing the simple road test but with
the two lights alternately disconnected will reveal whether or not they are
each set to the correct height, and will additionally reveal whether or not
the bright center spot of each light is properly centered on the road
straight ahead, and not aimed off to either side of the road.
Subsequent to the road test, I perform the additional procedure of shining
both lights together on the garage wall and making sure that the two narrow
bright bands are stacked one above the over. The dim region between the
two bright bands should be small but discernable. If I see two separate
bright bands, I will cover one headlight and make sure that the higher one
is the one on the right. If the left one is the higher one, I will raise
the right side and lower the left side so that they change places. If I
don't see two separate bright bands, I will raise the one on the right and
lower the one on the left until two separate bands appear.
I desired to modify the headlights so that when the headlight control
switch is on the low position, the high beam filaments would be partially
lit. Because the high beam coverage includes the region that is covered by
the low beams, the two low beam filaments would ideally be dimmed somewhat,
the left one more so than the right one. This would be straightforward if
it were possible to analytically determine what the voltage across the
individual filaments should be when the switch is on the low position.
However, this analysis is inordinately complex, such that only an
experimental approach would likely be successful. The resistors used to
divide the voltage would also consume power that is precious on the FJR.
I therefore decided to install dimmer controls, one to be shared by the two
high beam filaments, and one each for each of the two low beam filaments.
These dimmers would be functional only when the switch is on the low
position, and would have no effect when the switch is on the high position.
Initially I tried to find an old-fashioned rheostat (a length of resistive
wire coiled around a heat-tolerant ceramic core and with a movable
contact), but I discovered that they just aren't made anymore. They have
been replaced in DC applications by PWM (Pulse Width Modulation) devices
that achieve a similar result by opening and closing the circuit at a fixed
frequency and varying the proportion, of the cyclic period, for which the
circuit is closed.
I sent Mike Coan of Warm-n-Safe an e-mail asking him if he knew of any
potential issues with using the Heat-Troller as a headlight dimmer. Its
current rating was more than adequate at 16 Amps, but the problem that his
engineer discovered was that their latest version operates at 1 Hz, which
is very efficient for heated clothing but would produce a strobe effect if
used as a light dimmer. Mike found an earlier model that he believed
operated at 100 Hz or more, and I purchased it from him. At about that
same time I found an electrical supply house that sells a DC dimmer that
seemed to be suitable for this application, with operating frequency of 400
Hz and also rated at 16 Amps. This company is Euramtec, which distributes
the part number A-9040 made by AEC. I ordered a couple of them and figured
that between the HeatTroller and the AEC part, one or the other should work
adequately well.
A requirement that applies to both the Heat-Troller and AEC device is that
they must be placed between the load and ground, regulating the ground
connection for the load. That fact, together with the fact that the two
filaments in each H4 bulb are joined inside the bulb to what is by default
the common ground, meant that the polarity of the headlight connections
would have to be reversed. That is, the common ground would have to be
converted into a common +12V supply that arrives via headlight relay #1
(controlled by the ECU), and the wires that by default supply +12V
separately to the high and low filaments (via relay #2) would have to be
converted into separate ground paths for the high and low filaments.
Headlight relay #2 would have to be re-wired so that it would switch the
ground path alternately to the high or the low filaments instead of
switching +12V as it does normally.
Additionally, the high beam indicator lamp is supplied +12V via the high
beam output of relay #2. Since the high beam "output" of that relay would
be converted to supply a switched ground for the high beam filaments, the
polarity of the indicator lamp would also have to be reversed.
Alternatively, relay #2 could be replaced with a DPDT relay that would
provide a separate switched circuit for the indicator lamp, or a
supplemental SPST relay could be used for the indicator lamp. The cheapest
and simplest solution was to make some trivial changes to the meter panel's
printed circuit board, so that the side of that bulb that is presently
grounded is isolated from the ground, and the ground is replaced by a
connection to a location on the board where +12V is present whenever the
main switch is on. Although this was the cheapest and simplest solution,
it had an undesirable consequence as I learned.
I decided to use all three of the PWM devices that I had. The Heat-Troller
would be used to provide a supplemental ground path for both high beams,
by-passing relay #2 so that this ground path will be available to the high
beams even when the headlight switch is at the low beam position and relay
#2 provides a ground path only for the low beams. The two AEC components
would be individually inserted into the separate ground paths for the low
beam filaments, i.e., each would be placed between one of the low beam
filaments and relay #2.
The two pictures above are the schematics for the two supplemental wiring
harnesses needed to do this, showing how they must be joined to the stock
wire harness, that runs across the front cowling, at the headlight relays
and the headlight connectors. The two supplemental wiring harnesses are
joined by a 6-conductor connector, permitting the dimmers to be located
under the seat using also an extension cable that is inserted between the
mated 6-conductor connectors.
The picture above shows the AEC dimmers together with the plastic boxes
that I rigged to hold them.
The picture above shows the finished harness section that contains all
three PWM devices, ready to be connected to the other half of the
supplemental harness via the extension cable.
The picture above shows the supplemental harness #1 joined to the stock
wiring harness. I made it longer than was necessary in the middle section,
but that is okay because the excess wire fits easily into the recessed area
between the right and left headlight. Note the section wrapped in yellow
tape toward the left, which is the wire bundle to the auxiliary relay. The
auxiliary relay that I got at Radio Shack has a plastic tab with a hole and
the perfect location is screwed down to the windshield motor apparatus at
one of the four bolts that hold that apparatus to the aluminum stay. This
harness section also has, from left to right, battery + and - terminals, a
4-conductor cable that provides redundant + and - connections to the
Heat-Trollers used for the heated grips and the vest, the power supply for
the V1, the 6-conductor connector that joins to supplemental harness #2,
and the connector for the GPS power outlet.
The picture above shows the reverse side of the meter panel's printed
circuit board and the simple change that I made to it.
The picture above shows the placement of the dimmer controls under the
passenger seat. The boxes for the two AEC dimmers that control the low
beam filaments are a perfect in that location, with the knobs even
protected by the flat surfaces that support the rubber feet of the
passenger seat. The smaller knob on the shaft of the Heat-Troller's
potentiometer is mounted on the vertical plastic part, almost directly
under the far end of the mystery rubber thingie and near the upper right
corner of the picture. The 6-conductor connector is located just off the
right edge of the picture, on the other side of the cross member from the
Heat-Troller's potentiometer.
There is one minor annoyance. The high beam indicator lamp is dimly lit
when the switch is in the low position, just like the high beam filaments
themselves. As long as both it and the high beam filaments share the
primary ground path through headlight relay #2, the secondary ground path
through the Heat-Troller will also be available to the indicator lamp. This
can easily be corrected by using a miniature SPST relay to provide a
separate circuit for the indicator lamp, switched via the headlight switch.
If I had done this initially, I could have wired the miniature relay to
switch +12V and left the polarity of the indicator lamp unmodified. When I
next have a reason to remove the front cowling, I will add a miniature SPST
relay, but I will leave the printed circuit board as it is now and wire the
SPST relay so that it closes the ground circuit for the indicator lamp
under control of the headlight switch.
Notwithstanding the issue with the high beam indicator lamp, which is truly
trivial, this project was 100% successful when viewed as a personal
solution. I spent a good deal of time on this project, but I will be
rewarded each and every time that I ride the FJR after dark, for as long as
I own it. Even though I never had any expectations of this being a
solution that other riders might readily adopt, I do have some regret about
not having produced a solution that would help anyone else. Had this been
something that others could do in an hour or two, there is no doubt in my
mind that many others would do so and would be entirely pleased with the
result. Oh well. For those of you that actually read this, at least the
exercise was at least moderately educational; dare I say, enlightening?
Copyright © 2003, by H. Marc Lewis and Tom Barber.
All rights reserved.