HMMWV Project
Page 2: Upgrades!
Due to my bumbling, I ended up with a kit without the optional light and
sound modules. At least I was able to find them for purchase
separately, but they cost far more than they would have if I had just
ordered the model that included them to begin with. The
instruction manual shows a complex sound module which uses several
channels to do things like honk the horn, remotely adjust the volume,
and make a machine gun sound. The sound module they sent me,
despite having the right part number, doesn't do those things.
This is a much simpler sound module which just makes engine
noises. I can't find any evidence the complex module from the
instructions actually exists. The module I got has various engine
types built-in. By default, it uses a hideous 4-cylinder drift car
sound. One of the alternates is a nice diesel though. It is
very loud. The light module has brake lights, reverse
lights, turn signals, marker lights, and headlights. By default,
the headlights only come on with throttle which makes no sense, so I
wired them as switched lights.
I immediately ran into another problem. The model uses brackets to
retain the LED circuit boards, but these brackets were not included in
my model and cannot be purchased separately. I had to make my own
brackets out of styrene as shown. It worked reasonably well and
doesn't look too obnoxious. The provided clips work pretty well
for wire management. Then there was another problem. The
light module seem to assume a reversed throttle direction which means
the reverse lights come on when you go forward. There is no
reversing function on the module to fix it. You can reverse the
wires on the motor, but since the ESC only provides 50% power in reverse
that doesn't work either. I had to add an external servo reverser
to solve the problem.
Things get pretty busy under the hood with the light and sound modules
installed on top of the receiver and speaker and all the required
Y-harnesses. To complete my trifecta of follies, I fried my
speaker. Both the speaker and the power for the sound module use a
JST connector. I mistakenly plugged the speaker into the battery
which destroyed it. I had to order another speaker which took over
a month. I the end, it looks and works pretty well though.
Note to self: don't bother trying to save $70 on electronics that you
know you will add later anyway.
©2019 Eric Albrecht
