This is a great idea, and solves 2 problems: bulbs burning out, and keeping the 
right color. Most LEDs seem to like about 20mA of current. That would lead to 
(14.4-.7) V / 0.02 A = 685 Ohms (or something close) for the current limiting 
resistor. Power dissipation works out to I2 * R = 0.27W, so a 1/4W resistor is 
cutting it close - this is one of the larger SMT resistor packages, 1206 or 1210
I think.

-Erik

In message <950622193547_76360881@aol.com>  writes:
> 
> 
> To All:
> 
> When your indicator lights go out and it comes time to do the dreadful deed,
> consider doing away with the lights entirely by replacing them with
> high-intensity LEDs.  
> 
> While there are some fiddlee-bits involved in converting an incandescent lamp
> to LED, the basic idea is to crush the bulb, clean the cement from the brass
> base, desolder the center connector, and rebuild the thing incorporating an
> LED and current-limiting resistor.  For anyone experienced with surface-mount
> electronic components slightly smaller than a gnat's ass, the task is
> trivial.
> 
> The result is a colored lamp (Red, Yellow, or Green only) that will last for
> as long as your great-grandchild owns the vehicle.
> 
> -Bob

NSC Analog Automotive Systems  Tel. (408)721-3476  Fax (408)721-8292  M/S C2611