Monday, February 7, 2011

Electrical System Upgrades

I know there are people who ride their motorcycles all winter long, but I'm not one of them.  Whether that's because I'm not skilled enough or because I'm not dumb enough to try, I'll leave as an exercise for the reader :) but whatever the cause, there is a large block of time between November 1 and April 1 that my V-Strom just sits in the garage.  However, don't believe that means the Wee is neglected during this time; far from it.  This winter, at least, I am taking advantage of the down time to do some upgrades on the bike.  I've already posted the SW-Motech crash bar installation.  I'll also be changing the air filter, oil and oil filter before hitting the roads again this spring.

There are some electrical modifications I would like to make to the bike this winter, as well.  First, while the stock V-Strom headlights are pretty much amazing (much better than my Nissan Frontier, even), I'd like to add a little extra lighting to make the bike more conspicuous at night, so I'm adding fog lights.  Second, it can get a little chilly in south-central Alaska, even in the summer time, so I would like to add heated grips.  Third, after adding the TechMount PDA holder to the bike, I realized it would be good to have an auxiliary power port near the handlebars to supply power for my Android phone.  Using the GPS and Google Navigator sucks the battery dry much like an early '70s muscle car sucks a gas tank dry.  If I want to navigate with the Android for more than about an hour (especially in Alaska, where there are long stretches of highway with poor cellular service), I need a way to get juice to it.

Before deciding on these items, however, I had to take stock of the electrical load this would place on the bike.  From what I could find on-line, the V-Strom's alternator can supply about 40 amps of current.  EDIT: Pat (Greywolf) over at Stromtroopers suggests it may be a little lower -- 33A rather than 40A, with 10-12A available for accessories.. My thumbnail calculations suggest that my intended upgrades would add about 16 amps 5 amps:

  1. Fog lights: ~10 amps (2 x 55 watts @12 volts = 110 watts @ 12v = 9.2 amps) ~130mA (I found some LED H3 bulb replacements over at that I will be using instead of the halogen lights that came with my fog lights to keep current draw down);
  2. I am also replacing the stock incandescent brake lights with LEDs from, giving me one additional Amp (Note: they also sell straight 1157 replacemnt LEDs, but I decided to go with the motorcycle bulb after reading a report that the straight 1157s only illuminate directly behind the bike rather than lighting up the whole reflector);
  3. Oxford's Heated Grips: 4 amps (48 watts @ 12 volts);
  4. GPS power: 2 amps (my Android phone supposedly draws about 0.5 amp, but I'm providing a really large fudge factor for other devices).
The headlights draw about 10 amps, as do the high-beams and fog lights.  I can't imagine that the rest of the electrical system (ECU, brake lights, etc.) on the bike pulls 14 amps, so as long as I don't try to run fog lights and high-beam lights at the same time, I should be okay (anyone have experience to the contrary?). EDIT: based on Greywolf's suggestions (see link above), I think I should have more than enough power to run the new gadgets without overtaxing the electrical system on the bike. In fact, if my math is correct, I should still have 5-7A of current available, even with everything turned on.

After lots of trial and error, I decided to mount the fog lights at the bottom of the SW-Motech crash bars.  There is a fillet at the front of the crash bars where the bars wrap upwards around the engine.  That places the fog lights lower than I would like, where they could potentially be damaged by obstacles on the ground, but I when I tried to mount them inside the cowl, they didn't clear the forks.

Yes, it needs a longer bolt.  I'll fix it...eventually.
 Another problem I ran into with the fog light installation is finding a way to turn them on and off.  At first, I intended to buy a rocker switch from one of the electronic parts stores in town, but then I realized I would need a waterproof switch since I ride rain or shine.  I could trigger the relay with the current going to the headlights so that the fog lights would be on whenever the bike was running, but I wanted to be able to turn them on and off as needed.  I could just tie them into my high-beams, but I rarely use my high-beams (I don't want to blind oncoming traffic; just make myself a little more conspicuous).  After a lot of searching, I found a better solution. sells a nifty electronic module that ties into the on/off switch for your high-beam lights.  Trigger the high-beams for one second, and the autoswitch toggles power to another circuit.  If I connect the output wire from the autoswitch to a relay, I can turn the fog lights on and off at will.  Voila!  Problem solved :)

The next problem was trying to decide how to distribute power to all of these electronic gadgets.  I don't want to simply run a lead to the battery for each of these circuits, since that is a sloppy approach.  I don't want to clutter the battery with a slew of ring terminals, nor do I want to add more wiring than necessary to the bike.  I discovered that Suzuki offers heated grips as an option for the V-Strom, and that there is a power lead near the radiator that is designed to power the OEM heated grips.  This power lead only has power while the bike is running, so I can't inadvertently leave the heated grips or fog lights on when the bike is off.  This wire has a plastic quick-disconnect connector to allow you to easily add the heated grips after purchasing the bike, and makes a wiring harness that is designed to plug into this connector to provide power to your accessories.  Eastern Beaver recommends that you only use it for low power accessories ("less than 7 amps"), but that is plenty of power to trigger a relay for all of my accessories.  If I connect a wire from the battery to a relay, trigger the relay with the heated grip circuit, then run the relay to a bus bar, I can provide switched power for all of my accessories directly from the battery.  Here's the schematic for the circuit:

Although I don't much care for Microsoft, Visio is a pretty good product :)
I have ordered and received the autoswitch from Aerostich, and I have just placed my order for the Eastern Beaver wiring harness so I don't have any photos of the installation process...yet.  I'll be updating this post as I install the new electrical circuits, and review the products I install.

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