These are a direct replacement for the mini wedge incandescent instrument panel and dash lamps found in most domestic and import vehicles 1990-2015 except 2003-2006 GM models.
This dome top LED is compatible with bulb numbers: T5, 17, 18, 27, 37, 58, 70, 73, 74, 79, 85, 86, 206, 207, 286, 306, 307, 308, 406, 407 & 2721
Tips for color placement:
White to illuminate the instrument panel gauges
Green behind turn signal lenses
Amber behind check engine lenses
Red behind Oil, Alternator and Hi beam lenses
Blue behind Hi beam lenses
Example: If you are installing LED's behind your green turn signal indicator lenses, then you would want to install a green LED behind the lens. Using a white LED behind the green would tend to wash out the green color.
These LED's are dilemma but depending on how low your rheostat dimmer will cut the voltage depends on how dim the lights will be. These led's wont start to dim until they get below 9 volts.