Moved this over from Random Thoughts (Auto):
I already replaced the tail/brake light on the VT with an LED bulb I got at the auto-parts store. It was a tight fit, looked a bit brighter, but the light was more concentrated in one area of the lense then dispersed.
I'm guessing it looked like this?
Those only 'fire' in one direction, away from the socket. The light hitting the reflector is 'spillage' from the lateral sides of the LEDs. Mostly it just creates a 'hot spot' of light on the lens while not significantly illuminating the rest of the housing.
What you need are bulb replacements that 'fire' radially as well, such as these. The upper type is the one I bought for the 700 a while back. The lower is the newer 'SMD' type (named after the surface mount device LEDs that it uses) which are even more powerful, bright and power efficient; I would have used those if they were widely available and proven at the time I was shopping for one.
These radial types more closely mimic the light output pattern of a standard bulb and therefore can be used where focused spots are unwanted, or you need to light up an entire parabolic reflector (see my recent posts on my XJR thread for an example of the results). Even the older radial array type that I currently have in the taillight of the 700 is both brighter and more power efficient than the stock bulb (while not getting hot enough to heat and damage the aged lens).
I used 194-equivalent SMD radial types to replace the instrument lighting on the 700, something that's notoriously difficult to get LEDs to do because of their directionality (and the fact that the 700's pod requires laterally projected and reflected light in relationship to the socket - the "front" of the bulb is blocked and doesn't actually illuminate anything!) Behold the results.
Another thing was that the "tail-light out" light on the dash came on. Pardon the James Mayish question here, but how do you handle that? Do you remove the waring bulb? add a resistor? ignore it?
Easiest way to deal with it is, yes, just removing the bulb. There's another way to bypass it, but it's not necessarily worth bothering with.