This is a long post, but please read it all.  It has been updated to answer questions from the last six months, so please read it all.  Also see these posts for info on the brake light mod:

http://www.vision-riders.com/bb/forums/thread-view.asp?tid=3531&sta... 

http://www.youtube.com/watch?v=5-QPAMpVmhw 

With all the hoopla Victory gives their unique designs, I was dumbfounded to find that it used standard bulbs. Our new, state of the art, beautifully styled, high end machines use 1920's style light bulbs in the lighting system. And they suck a lot of power. There are 10 running light bulbs (6 on the rear fender, 4 in the front). All together (per the wiring diagram) they draw 9 watts each or 90 watts or 7 1/2 amps. LED's will knock this down to about 1/2 amp total.

Since my Vision is a Street model, I wanted to the look and reliability that LED lights provide, and to increase my visibility since I don't have the trunk mounted lights.

This project is so simple that this is not intended to be a "how-to", however, there are a few answers I can provide that may be of help or interest to others.

1. Bulbs. The taillight bulbs in the fenders and fairing are all standard 3157 dual filament bulbs. Just open up the tail light assembly or fairing (yesy you probably have to strip the fairing for this one - another reason to go for reliability), remove the existing bulbs, and replace them with the LED bulbs. They are not identified as 3157's on the wiring diagrams - they are sold at the dealer under a Victory part number only. If nothing else, this is a handy part to throw in the travel kit. The LED's will act funny if reversed so make sure that the running, brake and turn signal lights are correct. When you replace the bulb, be sure to check it out before you button everything up. NOTE:  The LED's can be put in backwards so check for proper operation before you button it up.  Just reverse the bulb.  Watch the turn signal.  If you put the bulb in backwards there, it will go completely off when flashing.  I like that look and it makes the turn signal more noticeable - so I left it backwards and turned the correct one around!  Just try it while it's apart; you'll see what I mean.  Be sure to use LED bulbs of the same color as your lens - white LEDs are not as bright as red LEDs behind a red lens (see COLOR below).

2. Reduced Alternator load. Depending on the LED bulbs you use, the alternator load can be reduced by up to 80 watts (~ 7 Amps) for running lights which are always on, 50 watts for the 2 brake lights when in use, and another 27 watts (2 Amps) during turn signal flashes. Figures are based on the wattage loads stated on the factory wiring diagrams in the maintenance manual. Reduced alternator loads means less alternator heat and improved reliability. Also, more Amps are now available for accessories without overloading anything, or for battery charging when running low RPM around town.

3. Brightness. If you do this be sure to get the brightest LED's possible. I have been putting LED's into tail lights for many years now, and the quality of bulbs has increased dramatically. Get the brightest bulb you can find. I simply get mine on Ebay and have never had a problem. They are now available with multiple surface mount high power LED's mounted in both a straight out and side firing pattern which takes advantage of the reflector. There is a new bulb, which I used, which has multiple LED emitters on a single chip, and has multiple chips on the top and sides, which lists as "high power" or SMD type LED bulb. DO NOT use the old style with only 12 or so LED's mounted to fire straight out only; they are only bright in a small area and do not "fill" the reflector with light. The new styles give out a light which is about equal to a standard 3157 bulb, according to my highly calibrated "eyeball tester".  Update - there are now high power LEDs that are rated at 3 watts or higher.  Get these!  I have them in my truck and they are amazingly bright.

4. Response time. LED's work at virtually the speed of light. They light up and go off as soon as power is on or off. Regular bulbs use a heated filament and have a lag time going on or off. To me, this provides a more noticeable light on which draws the eye quicker. It also makes the turn signals "snap" on and off which, I believe, makes them more visible.

5. Flash rate/bad bulb indicator. The Victory turn signals are controlled by a turn signal module, not a regular flasher (so it can't be replaced with an LED flasher module). It has a circuit which senses a bad bulb and increases the flash rate to let you know when one flasher bulb burns out. Installing LED's will fool the circuit into thinking you have a bad bulb so the flash rate will increase to about two per second instead of the normal one per second flash. The only way I know of to change this is putting a resistor (load equalizer) in parallel with the LED bulb to make it draw more power and simulate a bulb. If you go this route, be careful, because the resistor will get HOT. It is my belief, however, (corroborated by independent observers) that the faster flash rate makes the turn signal more visible to following cars. The one flash per second for flashers was not an ergonomic decision – it was based on the response time of a heated bulb filament. If you flash a regular bulb faster, it will not have time to go dark between flashes, and you simply get a mildly pulsing tail light instead of a flash. However, some VV's have flasher modules that don't like LEDs.  There are reports of no flash at all and/or cruise controls not working.  Since the flashers only use the top two rear LEDs and two front LEDs, it only takes two resistors (one for each direction) placed in parallel with the rear bulb to get things back to standard speed.  Since they are only on during turning, it is very little extra current draw in normal use.

6. Bulb life. I have never lost so much as one of the 32 LED's on the bulb, much less the whole thing, so burned out bulbs are a thing of the past. That's why premium cars come with LED tail lights (and the cool looks). The cost of all those things and the boards they are on is why they are not on bottom of the line cars and probably the Vision.

7. Tag light. This can also be changed over while apart. Use a 914 type bulb, but again, be sure to get one which has side firing LED's. I also painted the inside of the black housing silver to get more reflected light up. It is now more of a cool bluish light, and just as bright as before.

8. Logo Lights.  There have been several threads about how hard it is to replace the lighted badge lamps when they burn out.  Come on!!  You use LEDs everywhere else, put one in there too - you'll never have to replace it again.  You can get an LED version of virtually any light bulb.  I even had them in the instrument cluster on my Voyager XII.

9. COLOR.   Be SURE to get a bulb color that matches the color of the lens.  Regular bulbs only come in white.  But LEDs come in any color.  It is more efficient to use the same color.  DO NOT use white LEDs with a colored lens.  It will not be as bright as the colored LED of the same type.  For a more detailed explanation, start here:

http://www.glenbrook.k12.il.us/gbssci/Phys/Class/light/u12l2c.html

All in all, I consider this a worthwhile project with many advantages. If I have left anything out, let me know and I'll try edit this to answer. If you are happy with the standard set up, by all means continue to use it.

Since I put the LED's in mine last winter, I have tried several different bulbs and, unfortunately like many thing in life, bigger is better and more expensive.  I ordered mine off Ebay from Hong Kong and got them in 5 days.  

These babies look like part of the components we are using on our new aircraft lighting systems.  There are even LED landing lights now - and those pups are replacing bulbs rated at 450 watts, so there are some pretty powerful LED's out there.  I am going to try a pair soon to replace the 39 regular LED style I have in the front lenses (only in amber, of course).  UPDATE: I recently saw and ad for white/amber bulbs.  With clear lenses this would give you white running lights with amber turn signal to meet the legal turn signal color requirement.

 I order a lot of stuff off line and have made over 400 purchases from Ebay alone, with only 2 problems - both were new sellers with good prices (there's a moral there, I think).  Just look for a seller with a high number of feedbacks and a good % satisfaction rating.  Nobody can guarantee there won't be problem with an on-line order, but then I've had troubles at local stores, too.

The SMD lights have LED modules, not single LED's.  Each module has 3 LED chips in it, and they are very bright.  That is one of the problems with most LED bulbs.  I tried the 39 LED type with individual LED's but they weren't near as bright as a regular bulb.  The module style I got, similar to the above, are a lot closer in brightness.

Again, be ready for a change in flash rate.  Standard bulbs flash once per second, because that's as fast as they can respond.  The LED's are picked up as a burned out bulb by the flasher module so it flashes at two times per second.  But, since the LED's come on and off instantly, they really snap.  I think they are more noticeable.  The lights are not "going crazy" as has been said, they are just flashing faster because the module senses the change.  DoneETracey - you might like that because it would be flashing sooner and get you more noticed!!!

Update:

There have been a few problems reported.  One was of the cruise control not working (that's a stumper) with 4 LED's in the back, but working again with all 6 replaced.  Another user got nothing but a buzz from the turn signals - no flash.  This one might have been caused by TOO low a current to the LED's.  The high power ones draw more juice so this shouldn't be a problem but no guarantees.  Both of these problems are things that can only be evaluated with a drawing of what's inside the turn signal and cruise modules, and that isn't happening any time soon.

The next time you are behind an Acura SUV, look at the tail lights.  The ones I've seen lately use LED's in the brake lights, but bulbs in the turn signals.  One look at the difference when they flash and you'll see why LED's are so different.